What qwen3.8-flash-next-strata did

Let me start by exploring the working directory.

Let me plan the game carefully.

Key design decisions:
- Tile size 8 logical pixels, viewport 16x16 tiles = 128x128 logical px.
- Canvas scaled up (e.g., 4x = 512x512) with image-rendering: pixelated.
- Fixed timestep physics accumulator, e.g., 1/240 s substeps for accuracy.
- Levels: each exactly 16 tiles tall, several screens wide (e.g., 64-80 tiles wide).

Let me carefully design the physics.

Constants (tiles, seconds):
- gravity g = 22 t/s²
- terminal fall speed = 14 t/s
- ground acceleration = 18 t/s²
- max roll speed = 6 t/s
- ground friction = 12 t/s²
- air control = 0.4 * 18 = 7.2 t/s²
- landing restitution (no bounce) = 0.35
- bounce height = 3.0 tiles → v = sqrt(2*22*3) = sqrt(132) ≈ 11.489 t/s
- pad launch height = 6.0 tiles → v = sqrt(2*22*6) = sqrt(264) ≈ 16.248 t/s

Time to reach apex: v/g = 11.489/22 = 0.522 s. Total airtime ~1.044 s. At max roll speed 6 t/s, a full bounce covers ~6.26 tiles horizontally. Good — gaps should be ≤ ~4 tiles to be comfortable.

Height reached: 3 tiles exactly. Ball is 1 tile diameter. So a wall of 3 tiles tall can be cleared from standing? Ball resting on ground occupies 1 tile. Bouncing 3 tiles up means the ball's bottom rises 3 tiles, so its top is at 4 tiles above ground. To land on a ledge 3 tiles high, the ball's bottom must reach 3 tiles above the ground floor... apex bottom = 3 tiles above start bottom. Hmm, exactly 3 tiles means marginal. Let's make ledges 2 tiles high for safety, and use 3-tile max where there's slack. Actually "every wall the player can clear, they can clear from standing" — so ledges should be at most 2 tiles high to be safe (with 3 tile bounce, apex is exactly 3 tiles, so a 2-tile-high ledge is comfortable).

Careful: the apex height is exactly 3 tiles of rise for the ball's bottom. To land on a ledge whose top surface is 3 tiles above the ground surface, the ball's bottom must reach exactly 3 tiles — at apex vertical velocity is zero, so it just barely touches. In discrete simulation, it may not register. So keep ledges ≤ 2 tiles.

Also horizontal: to clear a gap, the ball must travel. With a 2-tile-high ledge, the ball reaches that height on the way up in t where 11.489t - 11t² = 2 → 11t² - 11.489t + 2 = 0 → t = [11.489 ± sqrt(132 - 88)]/22 = [11.489 ± 6.633]/22 → t1 = 0.2207, t2 = 0.8237. So the window where the ball is at or above 2 tiles is 0.603 s. At 6 t/s that's 3.6 tiles of horizontal travel at the ledge height. Plus the ball's own width (1 tile) helps. So a gap of ~3 tiles between ledges at 2-tile height is comfortable.

Let me be generous: gaps of 2-3 tiles max on critical path.

Collision: circle of radius 0.5 tiles vs solid tiles, resolved axis by axis. Actually simpler and robust: treat the ball as an AABB of 1x1 tile? No — spec says circle. Hmm, "Resolve circle-versus-solid-tile collisions one axis at a time". A circle vs axis-aligned tile edges. Let's implement properly.

Approach: ball position (x, y) = center, radius r = 0.5.

Horizontal pass: after moving x by vx*dt, find tiles overlapping the circle's bounding box in x-range [x-r, x+r], y-range [y-r, y+r]. For solid tiles, compute penetration. For a circle vs rectangle (tile), the proper resolution along x only: we can approximate by treating the circle as a square of side 2r for collision against tiles — but that changes corner behavior (snagging on corners). Hmm.

Better approach: For each solid tile overlapping the ball's bounding box, compute the closest point on the tile to the circle center. If distance < r, there's a collision. Resolve along x first: if vx > 0, push the ball left so that the circle's leftmost... hmm.

Let me think about a standard approach for circle vs grid tiles, resolving one axis at a time:

Step 1: move x. Step 2: resolve x collisions. For resolution along x, we consider the "vertical extent" of the circle at the tile. A common trick: for horizontal resolution, treat the ball as a vertical segment/box of width 2r and height 2r but only resolve if the overlap in y is more than a corner contact.

Alternative robust approach: swept circle against tile AABBs. For each solid tile, compute the Minkowski sum: the region where the circle's center cannot be = tile expanded by r (a rounded rectangle). Then the ball center must stay outside all expanded tiles. Resolving one axis at a time: after moving x, clamp x so the center is outside the expanded region considering only the y position.

Hmm, but the expanded region is rounded. If we treat the expanded region as a plain rectangle (tile expanded by r on all sides), that's equivalent to a square ball of side 2r — i.e., AABB collision. That gives corner snagging? Actually no: AABB vs grid is fine and never snags on corners because we resolve axis by axis. But the spec says circle. The visual is a circle; the collision being a 1x1 box is effectively what most tile platformers do. But the spec explicitly says "Resolve circle-versus-solid-tile collisions one axis at a time, horizontal first and vertical second, without corner snagging".

I'll implement a genuine circle resolution:

Horizontal pass: after x integration, for each solid tile T with rect [tx, ty, tx+1, ty+1]:
- Compute dy = clamp(cy, ty, ty+1) - cy → the vertical distance from center to the tile's y-interval. If |cy - clamp(cy,...)| > r, no possible collision.
- The circle's horizontal half-extent at the tile's nearest y-band: h = sqrt(r² - dy²) where dy is the vertical offset from the center to the nearest point in the tile's y-range. If cy is inside [ty, ty+1], dy = 0, h = r.
- Then the forbidden x-interval for the center is [tx - h, tx+1 + h]. If cx is inside that interval, resolve: if vx > 0, cx = tx - h; if vx < 0, cx = tx+1+h; if vx == 0, push to nearer side.

That's a proper circle resolution and it's smooth at corners (h shrinks near corners so the ball slides). Actually wait — corner snagging: consider the ball moving right and up into a wall corner. With this method, when the ball's center is below the tile's bottom by dy close to r, h → 0, so no collision. Good, that means the ball can pass under a tile corner if it's low enough... hmm, that's the correct circle behavior.

But there's a subtlety: when the ball is rolling on the ground and there's a wall, the ball's center is at y = ground_top - 0.5. The wall tile spans [wy, wy+1] where wy = ground_top - 1 ... Let's set up coordinates: y increases downward (screen coords). Ground tile top at y = G. Ball rests with center at y = G - 0.5. Wall tile occupies rows from G-3 to G (i.e., 3 tiles tall, top at G-3, bottom at G). For the wall tile at row G-1 (spanning y in [G-1, G]), cy = G-0.5 is inside [G-1, G] → dy=0, h=r=0.5. So the ball stops at cx = tx - 0.5. Correct.

For the tile at row G-3 (topmost of a 3-tall wall), spanning [G-3, G-2], cy = G-0.5 → nearest point is G-2, dy = 1.5 > r → no collision. Good.

Vertical pass similar with horizontal band.

Order: horizontal first, then vertical. Standard.

Ground detection: after vertical resolution, if vy > 0 and we clamped cy to tile top → landed. Set vy = 0, grounded = true, record landing.

Landing logic: when a landing is detected (transition from airborne to grounded, i.e., impact with vy > some threshold), if bounce held → vy = -vBounce. Else vy = -vy * 0.35 restitution, but if resulting |vy| small, settle.

Hmm, but "if bounce is held at the moment of landing, the ball is launched to its full bounce height — whether it was standing still or rolling flat out." So bounce applies on landing. What if the player is standing still and presses bounce? They land... they're already grounded. Need: if bounce is held and the ball is grounded, it should... Hmm. "There is no jump button and no instant jump impulse. Bounce is applied only when the ball lands."

So if you're standing still and hold bounce, nothing happens until you land. But if you're standing still on the ground and press bounce, you'd want to bounce. Hmm — how does a player initiate a bounce from standing? They must fall a tiny bit. Actually: if grounded and bounce is held, we can apply a small "unstick" — the ball leaves the ground with a tiny downward velocity? No.

Practical interpretation: when grounded and bounce is held (and wasn't held at the previous landing / newly pressed), the ball should bounce. The cleanest way: treat "landing" as the moment the ball transitions to grounded. If standing still, the ball is continuously grounded, no landing event.

Solution: when grounded and bounce is held, apply the bounce launch (vy = -vBounce) — but only once per press? If held continuously while grounded, it would bounce repeatedly which is actually consistent with "Holding bounce through a series of landings keeps the ball bouncing at that same full height". So holding bounce → continuous bouncing. That's fine and desirable.

But careful: if the ball is grounded and holding a direction, it rolls along the ground; each time it lands it bounces. If it's continuously in contact with the ground while rolling, do we get landings? With gravity applied each step, the ball accumulates downward velocity, then collides with the ground → that's a "landing" event each step. So holding bounce while grounded → continuous bouncing at full height. Good, that's the intended "hold bounce to keep bouncing".

And if bounce is not held while grounded, restitution 0.35 of a tiny impact velocity → settles. Good.

So implement: each physics step, apply gravity, integrate, resolve. When vertical collision with a floor occurs (ball moving down hits a solid top surface), that's a landing event: 
- if bounce held: vy = -vBounce
- else: vy = -vy * 0.35; if |vy| < threshold (say 1.5 t/s) → vy = 0.

With fixed dt = 1/240, gravity per step = 22/240 = 0.0917 t/s. So a resting ball accumulates 0.0917 downward each step, hits floor, restitution gives 0.032 → below threshold → settle. Good.

Bounce pad: on landing on a pad surface, vy = -vPad regardless of bounce held.

Now, what about landing on a wall side? Only floor landings count.

Ceiling: if ball moving up hits a ceiling, vy = 0 (or small bounce). Set vy = 0.

Now horizontal: ground acceleration 18, air control 7.2, max speed 6, friction 12 on ground when no direction held.

Friction "removes its speed over roughly half a second": from 6 t/s at 12 t/s² → 0.5 s. 

Now camera: viewport 16x16 tiles. Camera x follows ball, clamped to [0, levelWidth - 16]. Smooth: cam.x += (target - cam.x) * (1 - exp(-dt / tau)) with tau ~ 0.15s. Camera y fixed at 0 (level height = 16 exactly). No jitter.

Level height exactly 16 tiles. Level widths: L1 = 48, L2 = 56, L3 = 64, L4 = 72? Let's design.

Rendering: canvas 128x128 logical, scaled by CSS to e.g. 512x512 with image-rendering: pixelated. Actually let's render at 128*4 = 512 device px with a scale factor in the drawing (ctx.scale(4,4)) and draw with crisp rects. Simpler: canvas width=512 height=512, and use a SCALE=4, drawing everything in logical coords scaled. Use integer rounding for tiles to keep crisp. Camera position should be rounded to whole logical pixels (1/8 tile? or whole pixels) to avoid subpixel jitter/blur. Let's round camera to nearest 1/2 pixel... For crispness, round camera to whole logical pixels (i.e., multiples of 1/8 tile). Since camera is smooth, rounding to whole pixels gives 1-pixel steps — fine and crisp. Actually rounding to whole logical pixels at 4x scale = 4 device px steps, which might look slightly steppy but not jittery. Alternatively render at higher internal resolution. Let's render canvas at 128*4=512 and round camera to 1/4 logical pixel (i.e., device pixel). That's crisp at device level. Good: camera in tiles, convert to device px = cam*8*4 = cam*32, round to integer device px. Hmm, but then tile edges land on multiples of 32 device px — always crisp. And sub-tile camera offsets land on integer device px. 

Let me just do: canvas 512x512, draw in device pixels, compute camPx = round(camTiles * 32). Draw tiles at (tx*32 - camPx). All integers. Ball drawn as circle at sub-pixel position — fine, it's a circle, antialiasing on it is OK. Actually with pixelated scaling... we're not scaling, canvas is 512x512 displayed at 512x512. So antialiasing works normally. Let's display at 512x512 CSS px. Good — crisp.

Hmm, "scaled up crisply to suit a desktop browser" — 512x512 is good.

Let me use canvas internal 512x512 and CSS 512x512.

Now level data as strings. 16 rows per level. Characters:
- '.' empty
- '#' solid block
- '^' spike
- 'O' hoop
- 'C' checkpoint
- '*' crystal ball
- 'E' exit door (2 tiles tall) — mark with 'E' at bottom cell and 'e' at top cell? Let's use 'E' for the bottom cell and 'T' for top cell, or define exit as 'E' at bottom and the tile above must be empty; we treat exit as occupying 2 tiles: bottom 'E', top 'U'. Simpler: use 'E' for bottom and 'e' for top.
- 'P' bounce pad
- 'X' crumbling block
- 'S' spawn (ball start)

Let me design levels.

Coordinate: row 0 at top, row 15 at bottom. Ground typically at rows 14-15 (floor top at y=14). Ball rests with center at y = 14 - 0.5 = 13.5, occupying rows 13-14... wait, ball center 13.5, radius 0.5 → spans y in [13, 14]. So it occupies row 13. Good.

Bounce 3 tiles: center rises to 10.5, spans [10,11]. So the ball can be at rows 10-11 at apex. A ledge whose top surface is at y=12 (i.e., solid tiles at rows 12,13,14,15 → 2 tiles above the ground floor top of 14... wait ground floor top y=14 means solid rows 14,15. A ledge 2 tiles higher: solid rows 12..15, top surface y=12. Ball must land with center at 11.5, spanning [11,12]. Apex center 10.5 → yes, comfortably clears.

A ledge 3 tiles higher: top surface y=11, ball center must reach 10.5 = exactly apex. Marginal → avoid, or use bounce pad.

With bounce pad (6 tiles): center rises 6 → 7.5, spans [7,8]. Clears ledges up to 5 tiles high comfortably (top surface y=9, center 8.5 needed; apex 7.5 ✓).

OK. Let me design level 1: width 48.

Let me write out level 1 as a grid. I'll use a helper mental model. Let me define rows 0..15.

Level 1 (48 wide): "flat ground with no hazard on the first screen".

Screen 1 = columns 0-15. Flat ground rows 14,15 solid. Spawn at column 3.

Let me lay out:

Ground: rows 14,15 solid for all columns 0..47, except where gaps exist (gaps floored with spikes at row 15? "Every gap in a floor is floored with spikes rather than bottomless." So a gap in the floor at rows 14 → row 15 has spikes? Hmm, the floor is 2 tiles thick (rows 14,15). A "gap in the floor" means missing solid at row 14; then row 15 should be spikes. Let's make the floor: row 15 always solid (bottom bedrock), row 14 is the walkable surface with gaps; gaps in row 14 are filled with spikes '^' at row 14. That way the gap is floored with spikes. Good — spikes sit in the floor surface.

Hmm, but then a spike in the floor surface: the ball rolling along the ground would hit it. To cross, bounce over it. Spike lethal hitbox smaller region inside the tile — so a clean bounce over a floor spike is never frame-perfect.

Let's design: spikes occupy row 14 tiles (in the floor line). Ball bouncing over them at 3-tile height passes safely.

Level 1 layout plan (48 cols):
- cols 0-15: flat, safe. Hoop at col 8 (row 13, resting on ground — hoop collected on overlap; place hoop at row 13 so the ball rolling through collects it). Checkpoint 1 at col 12 (row 13).
- col 16-17: gap with spikes at row 14 (2-wide spike patch). Ball bounces over.
- Actually let's make level 1 gentle: a few spike patches 1-2 wide, one small step up (2 tiles), hoops along path.

Let me write it concretely. I'll build the map as 16 strings of 48 chars.

Let me define column ranges. I'll write row by row.

Level 1 (W=48):

Row 0-9: mostly empty.
Row 10: some ledge blocks for crystal detour.
Row 11-13: structures.
Row 14: surface (solid #, spikes ^, gaps).
Row 15: bedrock # everywhere.

Plan:
- cols 0..13: ground solid at 14,15. Spawn at col 2 (row 13). Hoop at col 6 (row 13). Hoop at col 11 (row 13). Checkpoint at col 14? Let's put checkpoint at col 14 row 13 — but col 14 is start of a spike patch. Hmm, checkpoint should be safe. Let's do: ground solid cols 0..15. Checkpoint at col 13.
- cols 16..17: spikes at row 14 (row 15 solid). So a 2-tile spike patch on the floor. Player bounces over.
- cols 18..23: ground solid.
- Hoop at col 20 row 13.
- cols 24..25: gap: row 14 spike, row 15 solid.
- cols 26..31: ground solid. Hoop col 28 row 13. Checkpoint col 31 row 13.
- Step up: cols 32..35 have solid at rows 12,13 (a 2-tile-high platform) with ground at 14,15 too. So a ledge at top surface y=12 spanning cols 32..35. Ball bounces up onto it. Hoop on top at row 11 col 34.
- Crystal: detour — high ledge. Let's put crystal at col 40 row 10, reachable via a 2-tile ledge at cols 38-39 (top y=12) then... hmm need it off critical path but reachable.

Let me restructure. Actually let me make the crystal reachable by bouncing up from a ledge.

Let me be concrete and careful. I'll write the map with explicit characters.

I'll define level 1 width 48.

Let me lay out columns 0-47 with a table of features:

Ground row 14: solid '#' everywhere except spikes at cols 16,17, 24,25, 36,37, 44? Let's see.

Actually let me think about "leave room": spike patches 2 wide, with at least 4 clear tiles before and after.

Level 1 detailed:

cols 0-15: flat ground (row14 #, row15 #).
  - spawn col 2 (S at row 13)
  - hoop col 7 (row 13)
  - hoop col 12 (row 13)
cols 16-17: spikes (row 14 ^)
cols 18-27: flat ground
  - hoop col 22 (row 13)
cols 28-29: spikes (row 14 ^)
cols 30-39: flat ground
  - checkpoint col 15? Hmm checkpoint should bank progress before hardest stretch. Let's put checkpoint at col 30 (row 13) and col 43.
  - hoop col 34 (row 13)
cols 40-41: spikes
cols 42-47: flat ground with exit at cols 45-46.

Hmm that's too flat/boring. Let's add a raised section.

Let me redo with more shape. Level 1: gentle but with a couple of ledges.

Level 1 (W=52):

Section A (cols 0-15): flat ground, spawn col 2, hoop col 6, hoop col 11. Safe first screen.
Section B (cols 16-19): spike patch cols 17-18 (row 14), ground cols 16,19 solid. Checkpoint at col 15 (row 13) — banks progress before first hazard. Good.
Section C (cols 20-27): raised platform: solid at rows 12,13 for cols 22-25 (a 2-tile step up), ground rows 14,15 solid beneath. So there's a step: player bounces onto the platform (top y=12). Hoop at col 23 row 11 (on top of platform). Then drop off the other side.
  Hmm, but the player could just roll under the platform? The platform is at rows 12,13, ground at 14,15 — there's a 2-tile-high corridor at rows 12,13? No: platform occupies rows 12,13, so the space above ground (rows 12,13) is blocked. So the player must go up. Actually the ball occupies rows 13 (resting on ground at row 14). If rows 12,13 are solid at cols 22-25, the ball rolling along the ground at col 21 hits a wall at col 22 (wall from y=12 to 14, 2 tiles tall). It must bounce up 2 tiles to land on top of the platform (top surface y=12). Bounce height 3 → fine.
Section D (cols 28-35): ground with spikes at cols 29-30, hoop col 33 row 13.
Section E: crystal detour — a high ledge. Let's put a ledge at rows 10,11 for cols 36-39 (top surface y=10) — that's 4 tiles above ground, needs bounce pad... no. Hmm.

Crystal detour should be reachable with normal bounces. Chain: ground (top y=14) → ledge top y=12 → ledge top y=10 → crystal at row 9. Each step 2 tiles. That works with normal bounces.

Let's do: cols 36-39: solid rows 12,13,14,15 (a 2-high block, top y=12). Then cols 40-43: solid rows 10,11,12,13,14,15 (top y=10). Crystal at col 41 row 9. Then the player drops back down. That's a deliberate detour (a side alcove going up). But it's on the critical path if the ground continues... Let's instead make it a side alcove: a raised platform above the main path, reachable from a lower platform.

Alternative: put crystal high up with a stack of platforms that branch off. E.g., main path continues on the ground; a side branch goes up: platform at cols 30-33 top y=12, then platform at cols 26-29 top y=10 (going back left), crystal at col 27 row 9. Player must bounce up and over. Off critical path since the main ground path continues below.

Hmm, but the platform at cols 30-33 top y=12 would block the ground path (rows 12,13 solid, ground at 14,15 → blocks). So it's on the critical path. To make it off-path, put the platform higher: cols 30-33 solid at rows 11,12 (top y=11) leaving rows 13 free for the ball to roll under (ball occupies row 13 when on ground at row 14). Wait ball resting on ground row 14 occupies rows 13 (center 13.5, spans 13..14). So a platform at rows 11,12 leaves a gap at row 13 → the ball can roll under. Yes! Ceiling at row 12, clearance of 1 tile — the ball fits exactly (spans [13,14], touching). That's tight but fine. Better: platform at rows 10,11 leaving rows 12,13 free → 2 tiles clearance. Comfortable.

So: crystal alcove: platform A at cols 30-33, rows 12,13 solid — no wait, that blocks.

Let me do the alcove as a raised shelf accessed from a step:
- Step block: cols 26-28 solid rows 12-15 (top y=12). This is on the critical path (must climb over) — fine, it's a step.
- From the top of that step (surface y=12, ball center 11.5), bounce 3 → center 8.5. Can land on a shelf at top y=10 (solid rows 10,11) at cols 23-25 (to the left, going back) → that's the detour. Crystal at col 24 row 9.

Hmm, going backwards is awkward. Let's make the shelf to the right but higher than the step: step top y=12 at cols 26-28; shelf at cols 30-33, rows 10,11 (top y=10). From step top (center 11.5) bounce → apex center 8.5, travels right; land on shelf top y=10 (center 9.5). Gap from col 28 to col 30 = 1 tile gap. Easy. Crystal at col 31 row 9. Then drop off the shelf back to ground.

But is the shelf on the critical path? The main path: after the step at cols 26-28 (top y=12), the player could drop off the right side to the ground at col 29+ if the shelf isn't blocking. Shelf at cols 30-33 rows 10,11 — leaves rows 12,13 free at cols 30-33. Player drops from step top (y=12) down to ground (y=14) at cols 29-33, passing under the shelf (rows 12,13 free). Clearance 2 tiles ✓. So the shelf is a genuine detour. 

Then continue to exit.

OK. Let me now actually write out the maps as strings. This is the tedious part. Let me write a script to help me verify counts and maybe render.

Actually, I'll write the maps carefully by hand and then verify with a Node script (node is available presumably). Let me check environment.

Let me plan all four levels.

**Level 1** — "Meadow"/flat, gentle. W=52.

Let me define per-column features. I'll construct rows programmatically in my head... risky. Better: I'll write the map strings and then run a Node script to validate: counts of O (6), C (2), * (1), E (2 cells), floor continuity, and simulate? Simulating a bot is hard. But I can at least validate counts and that spawn/respawn points aren't inside solids, and that every hoop is reachable-ish.

Let me just be careful and generous in design.

I'll write maps using a column-based description then generate strings with a script? That might be cleaner: write a Node script that builds the tile maps from feature lists and prints them as strings, then I paste them into game.js. Hmm, but the requirement says levels defined as data — array of tile map strings in the source. I can generate them with a script and paste the resulting strings. That's a good approach for accuracy.

Let me do that: write a Node script `mklevels.js` that constructs each level from feature lists (ground runs, blocks, spikes, objects), validates counts, and prints the 16-row strings. Then paste into game.js.

Let me design each level's features.

### Level 1 (W=52) — gentle
Ground: rows 14,15 solid for cols 0..51 (bedrock row 15 everywhere).
Features:
- Spawn col 2.
- Hoops: col 6 (row 13), col 11 (row 13), col 21 (row 13), col 36 (row 13), col 41 (row 13), col 47 (row 13).
  Wait, need hoops on critical path. Let's place: 6, 11, 21, 36, 41, 47. Hmm, one hoop on the shelf detour? No — hoops must be on critical path.
- Checkpoints: col 15 (row 13), col 34 (row 13).
- Spikes: cols 17-18 (row 14), cols 27-28 (row 14)... but I planned a step block at cols 26-28. Let me reorganize.

Revised Level 1 layout:
- cols 0-15: flat ground. Spawn col 2. Hoop col 6, hoop col 11. Checkpoint col 14.
- cols 16-17: spikes (row 14).
- cols 18-24: flat ground. Hoop col 21.
- cols 25-28: step block: solid rows 12,13,14,15 (top y=12). Player bounces up onto it. Hoop on top at col 27 row 11.
- cols 30-33: shelf solid rows 10,11 (top y=10) — detour. Crystal at col 31 row 9.
  Wait: from step top (cols 25-28, surface y=12), the player bounces right and can land on shelf (cols 30-33, top y=10) — 2 tiles higher, gap of 1 tile (col 29). Fine. Or just drop to ground.
  Hmm, but if the player is on the step top at col 28 and drops right, they land on ground at col 29 (y=14). Then rolling right under the shelf (cols 30-33, rows 10,11 solid, rows 12,13 free) — clearance 2 tiles ✓.
- cols 34-37: flat ground. Checkpoint col 34. Hoop col 36.
- cols 38-39: spikes (row 14).
- cols 40-45: flat ground. Hoop col 41.
- cols 46-47: spikes? Let's have a final small challenge: cols 46-47 spikes, then exit at cols 49-50.
  Hmm, exit door 2 tiles tall at cols 49 (bottom row 14? no). Exit door: two tiles tall, sitting on the ground: occupies rows 12,13 at col 49. Bottom cell 'E' at row 13, top cell 'e' at row 12. Wait if ground surface is y=14, the door occupies rows 12 and 13 (the ball resting at row 13 overlaps the door). Yes: door cells rows 12,13.

  Let me place exit at col 49: 'E' at row 13, 'e' at row 12.
- Hoop col 47 (row 13) just before exit. And spikes at cols 44-45.

Let me recount hoops: 6, 11, 21, 27(on step top, row 11), 36, 41, 47 → that's 7. Need exactly 6. Remove hoop at 41 or 47. Let's use: 6, 11, 21, 27, 36, 47. And spikes at 16-17, 38-39, 43-44. Checkpoints at 14 and 34.

Hmm wait, hoop at col 27 row 11 is on the step top — on critical path since the player must climb the step. ✓.

Actually is the step block at cols 25-28 blocking the ground path? Rows 12,13,14,15 solid at cols 25-28 → yes, the ball must climb. ✓ critical path.

Level 1 spikes: 16-17, 38-39, 43-44. Three spike patches, each 2 wide, with ≥5 clear tiles around. Gentle ✓.

Hmm, "Level 1 opens on flat ground with no hazard on the first screen" — first screen is cols 0-15 (camera starts centered on spawn col 2 → camera clamped to 0, showing cols 0-15). Spikes at 16-17 are just off-screen. ✓

### Level 2 (W=60) — bounce pads introduced
Palette: e.g., teal/cyan.

Design: introduce a bounce pad early in a forgiving spot (a pad that launches to 6 tiles, over a wide spike field).

Layout:
- cols 0-14: flat ground (rows 14,15). Spawn col 2. Hoop col 5, hoop col 10. Checkpoint col 13.
- cols 15-16: spikes.
- cols 17-22: ground. Hoop col 20.
- cols 23-24: bounce pads (row 14 surface = pad). Then a wide spike field cols 25-30 (row 14 spikes) — the pad launches 6 tiles, letting the ball fly over. Hmm: with a pad at cols 23-24, landing on it launches 6 tiles. Horizontal speed max 6 t/s. Pad launch v = 16.248 t/s, time to apex 0.7385 s, total airtime 1.477 s → horizontal distance up to 8.86 tiles. So a 6-tile spike field is easily cleared. But the player might land on the pad, bounce high, and land in the spikes if they don't have speed. Need "leave room": the spike field should be crossable also with a normal 3-tile bounce? Then the pad isn't on the critical path. Requirement: "Level 2 introduces bounce pads, with at least one on the critical path."

So make a gap that requires the pad: a high ledge (top y=9, i.e., 5 tiles above ground) reachable only via pad. From ground (center 13.5) pad launch apex center 7.5 → can land on a surface at y=9 (center 8.5) ✓, or even y=8 (center 7.5, marginal). So ledges up to 5 tiles above ground are pad-reachable comfortably (top y=9 → 5 tiles up).

Design: after the pad, a raised plateau at top y=9 spanning cols 26-33. Below it, cols 25-34 floored with spikes at row 14 (so a fall means death). Hmm, "blind drops onto a hazard" — avoid. Let's instead: the pad is at the bottom of a short descent, and the plateau is the only way forward because the ground path is blocked by a tall wall.

Simpler: a wall 4 tiles tall (top y=10) that can't be cleared by a normal bounce (needs 4 tiles up; normal bounce gives 3 → can't). Pad in front of it launches to 6 → clears easily.

Let's do:
- cols 0-14 flat ground. Spawn col 2. Hoops 5, 10. Checkpoint 13.
- cols 15-16 spikes (row 14).
- cols 17-21 ground. Hoop col 19.
- col 22-23: bounce pad (row 14 pad surface).
- cols 24-27: tall wall block solid rows 10..15 (top y=10, 4 tiles above ground). Wait, if the pad is at cols 22-23 and the wall starts at col 24, the ball lands on the pad and rises; with horizontal speed it will hit the wall side and slide down. It needs to get on top of the wall (top y=10). Pad apex center 7.5 → reaches y=10 surface (center 9.5) easily ✓. But the ball must travel right 1-2 tiles while rising. From pad at col 23 (center 23.5) moving right at speed v, it rises 4 tiles in t: 16.248t - 11t² = 4 → 11t² -16.248t +4 = 0 → t = [16.248 ± sqrt(264-176)]/22 = [16.248 ± 9.381]/22 → t1=0.312, t2=1.162. At speed 6, horizontal travel in 0.312 s = 1.87 tiles. Ball center at 23.5 + 1.87 = 25.37 → already past col 24's left edge (24 - 0.5 = 23.5 forbidden boundary). Hmm, the ball would collide with the wall's left face at cx = 23.5 while rising. So the player should bounce on the pad while moving right fast, then... they'd hit the wall.

Better: put the pad further from the wall, e.g., pad at col 22, wall at cols 26-29. Ball lands on pad at col 22 (center 22.5), launches up 6, travels right at 6 t/s. At t=0.312 it's at height 4 and x=24.4 — still left of wall face (25.5 forbidden). At apex t=0.7385, x = 22.5+4.43 = 26.93, height 6 (center 7.5, above wall top y=10 → wait center 7.5 means bottom at 8, which is above wall top 10 ✓). Then it descends; it will land on the wall top when center reaches 9.5, at t2 = 1.162 → x = 22.5 + 6*1.162 = 29.5. Wall spans cols 26-29 (x 26..30). So it lands on top at col 29 ✓. Good, with full speed. With less speed it lands on the wall's left face and slides down — then it must retry. That's fine (not frame-perfect) since the pad is right there.

Hmm, but if it lands on the wall face, it falls to the ground between pad and wall (cols 23-25) — safe, retry. ✓ Good design: forgiving.

Actually simpler and more robust: make the wall 3 tiles above ground (top y=11) — normal bounce reaches exactly 3 → marginal. Let's keep 4 tiles (top y=10) so normal bounce definitely can't (needs 4 > 3). ✓ pad required.

Continue level 2:
- Wall/plateau: cols 26-33 solid rows 10..15 (top y=10). Player on top. Hoop on top at col 29 row 9. Another hoop col 32 row 9.
  Hmm, need 6 hoops total. Let's place: 5, 10, 19, 29, 32, 45.
- Then from plateau top (y=10) the player continues right; plateau ends at col 33; drop down to ground at cols 34+ (ground rows 14,15). Drop of 4 tiles — must not land on spikes. Ground solid at cols 34-40 ✓.
- Checkpoint 2 at col 36 row 13.
- cols 41-42: spikes.
- cols 43-48 ground. Hoop col 45.
- Second pad section: pad at col 49-50, then... Let's add a second pad challenge: a gap floored with spikes cols 51-56 with a landing platform at cols 57-59? Hmm, level width 60.

Let me restructure the end of level 2 to be harder: 
- cols 41-42 spikes.
- cols 43-47 ground, hoop col 45.
- cols 48-49: bounce pads (row 14).
- cols 50-55: spike field at row 14 (6 tiles) — cross by bouncing (normal bounce: airtime 1.044 s at 6 t/s = 6.26 tiles horizontal; the ball must clear 6 tiles of spikes... marginal). With pad: easy. But is it required? The player could also cross with normal bounces if they hold bounce and keep speed: each hop 6.26 tiles — they'd land on a spike though, since the whole field is spikes. Hmm, they'd have to clear all 6 tiles in one hop: from col 49 (center 24.5... let me compute) — takeoff at x=49.5 (center), spikes occupy x 50..56, landing needs center ≥ 56.5 (on solid at col 56). Distance 7 tiles. Normal hop at max speed covers 6.26 tiles → not enough. Pad hop covers 8.86 → enough. So pad required ✓. But risky design: if the player bounces on the pad without enough speed, they land in spikes → death. Is that "frame-perfect"? No, it's a speed requirement, and they can retry from the pad. But the pad is at cols 48-49 and the ground before is cols 43-47 — they can run up. Reasonable.

Hmm, but "no blind drops onto a hazard" and "leave room". Let me make the spike field 5 tiles

Empty directory. Let me write the generator.

Wait — the check function requires support below for 'S' too, and for 'E'. Also 'D' is excluded from the support check (it's in 'OC*SE' — no, D is not in that string, good).

Also note: hoop at (27,11) — support below is (27,12) = '#' ✓. Crystal at (31,9) — below (31,10) = '#' ✓ (shelf rows 10,11). Level 4 crystal at (33,6) — below (33,7) = '#' ✓ (shelf rows 7,8).

Level 4 hoop at (25,8) — below (25,9) = '#' ✓ (plateau rows 9-14).

Let me run it.

All counts OK. Let me review the maps visually for problems.

L1: 
- Row 14: `################^^####################^^###^^#######` — spikes at 16,17 ✓, 38,39 ✓, 43,44 ✓.
- Row 13: `..S...O....O..C......O...####.....C.O..........O.E..` — S at 2, O at 6, O at 11, C at 14, O at 21, #### at 25-28, C at 34, O at 36, O at 47, E at 49 ✓.
- Row 12: `.........................####....................D..` — #### at 25-28 ✓, D at 49 ✓.
- Row 11: O at 27 ✓, #### at 30-33 ✓.
- Row 10: #### at 30-33 ✓.
- Row 9: * at 31 ✓.

Wait — row 11 has 'O' at col 27 and '####' at 30-33. Row 11: `...........................O..####..................` → index 27 = O ✓, 30-33 = #### ✓.

Hmm, but the step is at cols 25-28 rows 12,13. The hoop at (27,11) sits on top ✓.

The shelf at cols 30-33 rows 10,11. The crystal at (31,9) ✓.

Issue: the ball on the step top (surface y=12) at col 28 (center 28.5). The shelf starts at col 30 (x [30,31]). Gap at col 29 ✓. Verified earlier ✓.

L2:
- Row 14: `###############^^#####PP#################^^#####PP^^^^^#########`
  indices: 0-14 '#', 15-16 '^', 17-21 '#', 22-23 'P', 24-40 '#', 41-42 '^', 43-47 '#', 48-49 'P', 50-54 '^', 55-63 '#'. ✓
- Row 13: `..SO..####.........OC.....########..C........O..............E...`
  S at 2, O at 3, #### at 6-9, O at 19, C at 20, ######## at 26-33, C at 36, O at 45, E at 60 ✓.
- Row 12: `......####................########..........................D...` → #### 6-9 ✓, ######## 26-33 ✓, D at 60 ✓.
- Row 11: `........O..######.........########..............................` → O at 8 ✓ (on step top), ###### at 11-16 ✓, plateau 26-33 ✓.
- Row 10: `...........######.........########..............................` → shelf 11-16 ✓.
- Row 9: `.............*...............O..O...............................` → * at 13 ✓, O at 29, O at 32 ✓ (on plateau top y=10, ball occupies row 9 ✓).

Check: hoop at (3,13) — the ball spawns at col 2 and the hoop is at col 3, immediately collected. That's fine but maybe too trivial. Let me move it to col 4. Actually it's fine — a first hoop right in front of the spawn teaches the mechanic. Let me move it to 5 for a bit of rolling. Minor. I'll change to 5.

Hmm, also in L2 the step at cols 6-9 rows 12,13 and the hoop at (3,13) is before it ✓.

L3:
- Row 14: `################XXX######^^###XXXX#######^^#####^^^######^^#####`
  0-15 '#', 16-18 'X', 19-24 '#', 25-26 '^', 27-29 '#', 30-33 'X', 34-40 '#', 41-42 '^', 43-47 '#', 48-50 '^', 51-56 '#', 57-58 '^', 59-63 '#'. ✓
- Row 15: `##############################^^^^##############################` → spikes at 30-33 ✓.
- Row 13: `..S.O.####............O.....C.......O.......C.##.....O......O.E.` → S 2, O 4, #### 6-9, O 22, C 28, O 36, C 44, ## 46-47, O 53, O 60, E 62 ✓.
- Row 12: `......####....................................##XXX...........D.` → #### 6-9 ✓, ## 46-47, XXX 48-50 ✓, D 62 ✓.
- Row 11: `........O.######................................................` → O at 8 ✓, ###### 10-15 ✓.
- Row 10: `..........######................................................` ✓
- Row 9: `............*...................................................` ✓ crystal at 12.

Wait: the shelf at cols 10-15 rows 10,11 and the step at cols 6-9 rows 12,13. Gap at col 10 between the step's right edge (col 9) and the shelf's left edge (col 10)? The step occupies cols 6-9; the shelf occupies cols 10-15 at rows 10,11. So the shelf's left face is at x=10, directly adjacent to the step's right edge at x=10. Hmm! Earlier I analyzed this exact problem: the ball rising at col 9.5 would be blocked by the shelf's left face at col 10.

Let me re-check: the ball on the step top (surface y=12, center 11.5) at center x = 9.5 (right edge of the step). The shelf tile at col 10 spans x [10,11], y [10,12) (rows 10,11). The ball at center (9.5, 11.5) spans x [9,10], y [11,12] → x overlap with [10,11]? Only touching at x=10 → zero overlap ✓. Now the ball bounces (rise 3, apex center 8.5) and moves right. At center x = 10.0, y = 11.5 - rise. If rise < 1.5, the ball's y-span [11-rise, 12-rise] overlaps [10,12) → yes for rise < 2 → collision with the shelf's left face → pushed back to x = 10 - h.

Hmm, so the ball must rise above y=10 (bottom < 10 → center < 9.5, rise > 2) before it can move right past x=9.5+... Let's compute: the ball can move right only when it's not overlapping the shelf tile. Overlap in x requires center x > 9.5. Overlap in y requires center y - 0.5 < 12 and center y + 0.5 > 10 → center y ∈ (9.5, 12.5). So while the ball's center y > 9.5, it can't pass x > 9.5.

The ball rises to apex center 8.5 ✓ (above 9.5). So it can pass once risen > 2 tiles. Time: rise > 2 between t1=0.221 and t2=0.824. During that window it must travel right from 9.5. But at the moment it starts, vx might be 0 (killed by the wall contact). Air accel 7.2 t/s². From t=0.221 to 0.824 (0.603 s), starting at vx=0: distance = 0.5*7.2*0.603² = 1.31 tiles → reaches x = 10.81 at t=0.824 where rise = 2 (center 9.5). Hmm, at x=10.81 and center y = 9.5, the ball's bottom = 10 = the shelf top surface → it lands on the shelf ✓ (col 10).

But wait, during the rise, before t=0.221, the ball is pushed back to x=9.5 (blocked). At t=0.221 the ball's center y = 9.5, so it can start moving right. Actually it's continuously being blocked until y < 9.5. Then it accelerates right. It travels 1.31 tiles in the window and lands at x≈10.8 on the shelf ✓.

Hmm, but actually the ball's vx isn't zeroed continuously — each step it accelerates right (air accel) and gets zeroed by the collision. So it stays at x=9.5 until y < 9.5. Then it accelerates. It lands on the shelf at col 10 ✓.

But hold on: does it land on the shelf or does it fall back to the step? At t=0.824 the ball's rise is exactly 2 (center 9.5 = shelf top - 0.5) and x = 10.81 → over the shelf tile (col 10 spans [10,11]) ✓ → it lands ✓.

Actually it lands slightly before: as soon as its bottom reaches 10 while over the shelf. It's over the shelf (x > 9.5) from the start of the window. So it lands at t=0.824 at x=10.81 ✓ on the shelf ✓.

If the player holds right the whole time at higher initial speed: e.g., the ball arrives at the step top rolling at 6, then bounces. At t=0.221, x = 9.5? No — if the ball is rolling on the step top at speed 6, it would run off the step's right edge (center 9.5) and fall. Hmm, the ball on the step top is supported while center x ∈ [5.5, 9.5]. Beyond 9.5 it falls off. So at speed 6 it falls off the step and drops to the ground (2 tiles) — missing the shelf.

Hmm. So to get the crystal, the player must stop at the step's right edge (or bounce before) and then bounce up. That's a deliberate detour ✓ good — "the crystal ball takes a deliberate detour".

But is it reachable? The player must be at the step's right edge, hold bounce, and rise; then hold right. It works as computed ✓. But it's a bit fiddly because the shelf's left face is right at the step's edge.

Let me improve: shift the shelf right by 1 so there's a gap: shelf cols 11-16 for L3 (gap at col 10). Then the ball at the step edge (9.5) rises freely (no wall) and can move right. Let's recompute for L3 with shelf cols 11-16 rows 10,11:
- Rise 2 (to land on shelf top y=10, center 9.5): t2 = 0.824. Starting at x=9.5 with vx=0 (if blocked... no, no wall now) — the player holds right while on the step: they'd run off the step at 9.5 and fall 2 tiles to the ground. To gain height they must bounce.
- If they bounce at the step top with vx = v: land at x = 9.5 + v*0.824 (if not blocked). For the shelf at cols 11-16 (x [11,17]), landing needs center x ∈ [10.5, 17.5] roughly. v=2 → 11.15 ✓; v=6 → 14.44 ✓. Good wide window ✓.
- But the ball must clear the shelf's left face at x=11: while the ball's center y > 9.5 it can't pass x > 10.5. At speed 6, the ball reaches x=10.5 at t=0.167, rise = 1.915-0.306 = 1.61 → center 9.89 > 9.5 → blocked! It would hit the shelf's left face at x=10.5.

Hmm. So the ball needs a 1-tile gap between the step edge and the shelf face so it has time to rise. Let's compute the needed gap: the ball needs rise > 2 (center < 9.5) to pass over the shelf top. At speed 6, rise = 2 at t1 = 0.221 → x = 9.5 + 1.33 = 10.83. The shelf's left face blocks the ball when center x > faceX - 0.5 where faceX = shelf left x. So we need shelf left x > 10.83 + 0.5 = 11.33 → shelf starts at col 12 (x=12) ✓.

With shelf at cols 12-17: at speed 6, the ball is above the shelf top from x=10.83; landing at t2=0.824 → x = 9.5+4.94 = 14.44 → col 14 ✓ on the shelf. At speed 3: rise 2 at t1=0.221 → x = 10.16; blocked until... the ball is blocked at x = 11.5 until center y < 9.5, which happens at t=0.221 (before reaching 11.5 at speed 3? x at t=0.221 = 10.16 < 11.5 ✓ not blocked). Landing at t2=0.824 → x = 11.97 → col 11 (not shelf, shelf starts at 12) → center 11.97 spans [11.47,12.47] → overlaps col 12 ✓ lands on the shelf's left edge ✓.
At speed 2: landing x = 9.5+1.65 = 11.15 → spans [10.65,11.65] → no overlap with col 12 [12,13] → falls to the ground ✓ (safe, retry).
At speed 6: 14.44 ✓.

Good: speeds ≥ ~2.5 work, no blocking. Shelf cols 12-17 for L3, crystal at (14,9).

Hmm, but the shelf at cols 12-17 rows 10,11 — ground clearance rows 12,13 ✓.

Similarly for L1: step cols 25-28 (right edge x=29), shelf cols 30-33 (left face x=30). At speed 6, the ball needs rise 2 by x = 28.5+1.33 = 29.83, and the face blocks at center x > 29.5. So at speed 6 the ball is blocked at x=29.5 (reached at t=0.167, rise 1.61 < 2) → blocked → it slides and falls back. Hmm! So at full speed the player can't get onto the L1 shelf.

At speed 3: x at t1=0.221 → 28.5+0.66 = 29.16 < 29.5 ✓ not blocked. Landing at t2=0.824 → x = 28.5+2.47 = 30.97 → col 30 ✓ on the shelf.
At speed 4: x at t1 = 28.5+0.88 = 29.38 < 29.5 ✓ barely not blocked. Landing x = 28.5+3.30 = 31.8 ✓.
At speed 5: x at t1 = 29.6 > 29.5 → blocked at 29.5 → the ball is stopped horizontally, rises to apex 8.5, then falls; while above 9.5 it can move right again... Let's see: blocked at x=29.5 until center y < 9.5 (rise > 2), which happens at t=0.221. But at that moment vx has been zeroed. Then it accelerates right from 0: from t=0.221 to t=0.824 (0.603 s) → 1.31 tiles → x = 30.81 at t=0.824, rise = 2 → lands on the shelf at col 30 ✓.

Oh interesting — so even at full speed it works, because the ball gets blocked, then accelerates in the air. Let me redo: the ball is blocked at x=29.5 with vx=0. It keeps rising. At t=0.221 (rise 2, center 9.5), the shelf tile no longer overlaps in y (the ball's y-span [9,10] vs tile y [10,12) → touching at 10, zero overlap) → free to move right. It accelerates at 7.2 t/s². It needs to travel right enough to land on the shelf: it lands when its bottom reaches 10 (center 9.5) — but it's already at 9.5 at t=0.221 and rising. It falls back to center 9.5 at t=0.824, by which time x = 29.5 + 1.31 = 30.81 ✓ over the shelf → lands ✓.

Great, so it works at any speed. But wait — at t=0.221 the ball is at center 9.5 exactly at the boundary; as it accelerates right, does it re-collide? At x slightly > 29.5 and y slightly < 9.5 (still rising), the y-span [y-0.5, y+0.5] with y < 9.5 → top of the tile is 10, ball bottom = y+0.5 < 10 → no overlap ✓ free.

Then it descends; when the ball's bottom reaches 10 it's over the shelf → lands ✓.

OK so L1's crystal is reachable at any speed ✓.

But hmm, at very low speed (the player bounces in place at the step edge without holding right), they'd land back on the step. They need to hold right ✓ natural.

Now for L3, with the shelf at cols 10-15 (left face at x=10, step right edge at x=10): the ball at x=9.5 blocked until rise > 2 (t=0.221), then accelerates 1.31 tiles → x = 10.81 at t=0.824 → lands on the shelf at col 10 ✓. Works too!

OK so both work. But there's a subtlety: at t=0.221 the ball is exactly at the boundary y=9.5 and x=9.5. Then it accelerates right. At the next step, x = 9.5 + tiny, y = 9.5 - tiny (still rising). Overlap check: x-span [9,10+ε] overlaps tile x [10,11] ✓; y-span [9-ε, 10-ε] vs tile y [10,12) → no overlap ✓. Good.

Hmm, but wait: the collision check uses dy = distance from center y to [ty, ty+1]. For tile row 10 (y [10,11]): center y = 9.5 → dy = 0.5 → h = sqrt(0.25-0.25) = 0 → forbidden x interval [10-0, 11+0] = [10,11]; the ball center x=9.5 is not in [10,11] ✓ no collision. For tile row 11 (y [11,12]): center 9.5 → dy = 1.5 > r → skip ✓.

At center y = 9.6: dy = 0.4 → h = sqrt(0.25-0.16) = 0.3 → forbidden [9.7, 11.3]; ball center 9.5 not in it ✓.
At center y = 9.8: dy = 0.2 → h = 0.458 → forbidden [9.542, 11.458]; ball center 9.5 not in it (9.5 < 9.542) ✓ barely.
At center y = 10.0: dy = 0 → h = 0.5 → forbidden [9.5, 11.5]; ball center 9.5 → "b.x > lo && b.x < hi" → 9.5 > 9.5 false → no collision ✓ (strict inequality).

OK, marginal but consistent. To be safe, let me shift the L3 shelf to cols 11-16 (1-tile gap at col 10) so the geometry is less marginal. Then:
- Step right edge x=10, shelf left face x=11.
- The ball at the step edge (center 9.5) bounces; blocked? The shelf tile at col 11: forbidden x interval starts at 11 - h ≥ 10.5. The ball at 9.5 is free ✓. It accelerates right. At speed 6 it reaches 10.5 at t=0.167 (rise 1.61, center 9.89): dy = 10 - 9.89 = 0.11 → h = 0.488 → forbidden [10.512, 11.488+... wait hi = tx+1+h = 11+1+0.488 = 12.488]. Ball center 10.5 < 10.512 ✓ barely free. Hmm, marginal again.

Let me instead just make the shelf 2 tiles away: cols 12-17 for L3. Then the face is at x=12, forbidden starts at 11.5. At speed 6, the ball reaches 11.5 at t=0.333 → rise = 3.83-1.22 = 2.61 → center 8.89 → dy = 10-8.89 = 1.11 > r → no collision ✓ fully free. Landing at t2=0.824 → x = 9.5+4.94 = 14.44 → col 14 ✓ on the shelf (12-17) ✓.
At speed 3: landing x = 11.97 → col 11? spans [11.47,12.47] → overlaps col 12 ✓ lands ✓.
At speed 2: 11.15 → spans [10.65,11.65] → no overlap with col 12 → falls to ground (safe) → retry ✓.

Good. L3 shelf cols 12-17, crystal at (14,9).

Similarly for L2: step cols 6-9 (right edge x=10), shelf cols 11-16 (left face x=11). Same as the L3 analysis → at speed 6 it's marginal but works; at speed 3 landing x = 9.5+2.47 = 11.97 → col 11 ✓ on the shelf (11-16) ✓. Let me shift L2's shelf to cols 12-17 too for consistency and safety. Crystal at (14,9).

Hmm, but L2's shelf at cols 12-17 rows 10,11 — ground clearance ✓.

And L1: step cols 25-28 (right edge x=29), shelf cols 30-33 (face x=30). Marginal-ish but works. Let me shift to cols 31-34 (face x=31) for safety. Then at speed 6: the ball reaches x=30.5 (forbidden start) at t=0.333 → rise 2.61 → center 8.89 → dy = 10-8.89 = 1.11 > r ✓ free. Landing at t2=0.824 → x = 28.5+4.94 = 33.44 → col 33 ✓ on the shelf (31-34) ✓. At speed 3: landing x = 28.5+2.47 = 30.97 → spans [30.47,31.47] → overlaps col 31 ✓ lands ✓. At speed 2: 30.16 → spans [29.66,30.66] → no overlap with col 31 → falls to ground ✓ safe retry.

Good. L1 shelf cols 31-34, crystal at (32,9).

Hmm, but then the checkpoint at 34 (row 13) is under the shelf ✓ fine. And hoop at 36 ✓.

Now L4's crystal shelf at cols 31-35 rows 7,8 — verified ✓ (plateau right edge x=29, shelf face x=31, 2-tile gap ✓).

Let me re-verify L4 crystal route with the shelf at 31-35: from the plateau top (center 28.5, y 8.5), bounce → rise 2 → land on shelf top y=7 (center 6.5) at t2=0.824 → x = 28.5+4.94 = 33.44 → col 33 ✓ (shelf 31-35) ✓. At speed 3: x = 28.5+2.47 = 30.97 → spans [30.47,31.47] → overlaps col 31 ✓ lands ✓. Blocked check at speed 6: reaches x=30.5 at t=0.333 → rise 2.61 → center 5.89 → shelf tile rows 7,8 → y [7,9): dy = 7-5.89 = 1.11 > r ✓ free ✓.

Crystal at (33,6) ✓ (already).

Now let me also double check L4's hoop at (33,13) — under the shelf ✓, and the checkpoint at (30,13) ✓.

Let me update the generator and re-run.

Also L2: move hoop from (3,13) to (5,13).

Let me also reconsider L2's plateau: cols 26-33 rows 10-14. The pad at 22-23. Verified ✓.

One more check for L2: the ball lands on the plateau at col 29 (speed 6). Hoops at (29,9) and (32,9) ✓.

Now, another important check: in L2, after the plateau, the player drops off the right edge at col 33 (center 33.5) → falls 4 tiles → lands around col 37 ✓ ground. Checkpoint at 36 ✓.

Hmm, but the checkpoint at 36 is right in the landing zone — fine.

Now let me also verify L3's raised bridge: step cols 46-47 rows 12,13 (top y=12), X at row 12 cols 48-50 (top y=12) — continuous ✓. Spikes at row 14 cols 48-50 ✓. Ground at cols 43-47 row 14 ✓ (wait, cols 46-47 have solid rows 12,13 AND 14,15 → the step sits on the ground ✓).

The player must climb the step at col 46 (2 tiles) ✓ from the ground at col 45.

Then run right across X at 48-50, then drop at col 51 to the ground ✓.

Hmm: is the drop from y=12 at col 50 (center 50.5) to the ground at col 51 safe? The ball leaves the bridge when center x > 50.5 → falls onto col 51 (row 14 solid ✓) ✓.

But careful: the spikes at row 14 cols 48-50 are directly below the X bridge. If an X collapses while the ball is on it → death ✓ (respawn at 44).

Now, one more: the X blocks at row 12 cols 48-50 collapse → the ball could be standing at col 50 when it collapses → falls onto spikes at row 14 col 50 → death ✓.

Fine.

Let me also double check L3's intro pit: X at row 14 cols 16-18, bedrock row 15 '#'. When X collapses, the pit floor is y=15. The ball in the pit: center 14.5. Can it get out? Bounce 3 → center 11.5. The pit rim is at y=14 (cols 15, 19). To land on the rim, the ball's center must reach 13.5 while over col 15 or 19 ✓ easily ✓.

But also: the pit is 3 tiles wide (cols 16-18, x [16,19]). The ball at center 14.5 must move horizontally to x ≤ 15.5 or ≥ 19.5 to be over the rim... Actually to land on the rim tile at col 15 (x [15,16], top surface y=14), the ball's center must be within [14.5, 16.5] and its bottom reach 14. From the pit at center 16.x, moving left to 15.5 ✓ easy.

Hmm, careful: while in the pit at center y=14.5, moving left, the ball's x-span... the pit walls at col 15 (row 14, y [14,15)) — the ball at center (15.5, 14.5): for tile (15,14), dy = 0 (14.5 ∈ [14,15]) → h = 0.5 → forbidden x [14.5, 16.5] → the ball center 15.5 is inside → collision → pushed to 16.5. So the ball can't move into the pit wall at ground level ✓ (it's a 1-tile-deep pit with walls). It must bounce up: at center y < 13.5 (bottom < 14), it can move left past x=15.5? For tile (15,14): center y = 13.4 → dy = 0.6 > r → no collision ✓ free. Then it descends onto the rim ✓.

Good, escapable ✓.

Now let me finalize the generator changes and re-run.

Also, I realize I should double check L1's spike at 16-17 relative to the checkpoint at 14: the respawn at col 14 (center 14.5) — 1.5 tiles from the spike at col 16 (x [16,17]) ✓ safe.

L3 checkpoint at 28, spikes at 25-26 → respawn at 28.5, spikes at x [25,27] → 1.5 tiles away ✓ safe.

L4 checkpoint at 49, spikes at 46-47 → respawn 49.5, spikes x [46,48] → 1.5 tiles ✓ safe.

L2 checkpoint at 20, spikes at 15-16 ✓ safe. Checkpoint at 36, spikes at 41-42 ✓ safe.

Good.

Now let me update gen.js.

All good. Now let me write the game.

Wait, L4 row 9: `......................#######...........................XXXX####XX......` → cols 22-28 plateau ✓, X at 56-59 ✓, #### at 60-63 ✓, XX at 64-65 ✓.

Row 14 L4: `#############^^#PP##################XXXX######^^###PP^^^^^^^####^^######`
- 0-12 '#', 13-14 '^', 15 '#', 16-17 'P', 18-35 '#', 36-39 'X', 40-45 '#', 46-47 '^', 48-50 '#', 51-52 'P', 53-59 '^', 60-63 '#', 64-65 '^', 66-71 '#'. ✓

Row 15 L4: `####################################^^^^################################` → spikes at 36-39 ✓.

Good.

Now write index.html, style.css, game.js.

Let me write game.js in chunks. First chunk: constants, level data, palettes, parsing.

Let me carefully write it.

I'll write the whole game.js in ~3 writes.

Chunk 1: header, constants, LEVELS data, palettes, parse/validate.
Chunk 2: input, physics, game state.
Chunk 3: rendering, HUD, loop.

Let me write.

For palettes I'll include per-level colors.

Let me define the level definitions:

```js
const LEVELS = [
 { name:'MEADOW',
   pal:{ bg:'#0e2118', bgAlt:'#12291e', block:'#24603f', blockTop:'#3f9a63', crumble:'#3f7a55', door:'#c9d6cf' },
   map:[ ... ] },
 ...
];
```

Common object colors:
```js
const COL = {
  ball:'#ff3b30', ballEdge:'#5c0f08',
  hoop:'#ffd23f', hoopEdge:'#7a5c00',
  cpOff:'#3d6b85', cpOn:'#5ad1ff',
  crystal:'#c58bff', crystalIn:'#f0dcff',
  spike:'#f4f7ff', spikeEdge:'#9fb0c4',
  pad:'#7ee787', padBase:'#22402a',
  crack:'#1a1a1a',
  doorClosed:'#9aa3ad', doorOpen:'#eafcff'
};
```

Hmm, for L3 the block color is purple; crumble blocks should be visibly distinct from plain blocks — I'll draw them with cracks and a slightly different hue.

Now the parse:

```js
function parseLevel(def){
  const map = def.map.map(r=>r.split(''));
  const h = map.length, w = map[0].length;
  ...
}
```

Store: level.grid (array of arrays), level.w, level.h, level.spawn {x,y}, level.hoops[], level.checks[], level.crystal, level.exit{x,y}, level.pad set, level.crumble list.

Solid test function needs access to the current level and crumble states and doorOpen.

Let me write:

```js
function tileAt(x,y){
  const L=level;
  if(x<0||y<0||x>=L.w||y>=L.h) return '#';   // out of bounds = solid
  return L.grid[y][x];
}
function isSolid(x,y){
  const c=tileAt(x,y);
  if(c==='#'||c==='P') return true;
  if(c==='X') return !crumbleGone(x,y);
  if(c==='E'||c==='D') return !doorOpen;
  return false;
}
```

Crumble state: a Map keyed by `x+','+y` with {t: timer, state:'idle'|'shake'|'gone'}.

Update crumbles each step.

Now the ball.

Let me write the physics step.

```js
function stepPhysics(dt){
  const b=ball;
  const left = keys.left, right = keys.right, bounce = keys.bounce;
  const dir = (right?1:0) - (left?1:0);
  if(dir!==0){
    const a = b.grounded ? ACC_G : ACC_A;
    b.vx += dir*a*dt;
    if(b.vx>MAXV) b.vx=MAXV; if(b.vx<-MAXV) b.vx=-MAXV;
  } else if(b.grounded){
    const s=Math.sign(b.vx);
    if(s!==0){ b.vx -= s*FRIC*dt; if(Math.sign(b.vx)!==s) b.vx=0; }
  }
  b.vy += GRAV*dt; if(b.vy>TERM) b.vy=TERM;
  b.x += b.vx*dt; collideX(b);
  b.y += b.vy*dt; const land = collideY(b);
  b.grounded = !!land;
  if(land){ handleLanding(land); }
  ...
}
```

handleLanding: 
```js
function handleLanding(l){
  const b=ball;
  const c = tileAt(l.tx, l.ty);
  const impact = l.vy;
  if(impact > 2.0) ball.squash = Math.min(0.5, impact/20);
  if(c==='X') triggerCrumble(l.tx,l.ty);
  if(c==='P'){ b.vy = -V_PAD; b.stretch=...; }
  else if(keys.bounce){ b.vy = -V_BOUNCE; }
  else { let v = -impact*REST; if(Math.abs(v) < 1.4) v = 0; b.vy = v; }
}
```

Hmm, careful: `l.vy` is the pre-collision vy. But collideY sets b.vy=0 during resolution. I saved vy in the landing record ✓.

Also, if multiple tiles land, we take the last one. But if one of them is a pad, we should prefer the pad. Let me collect all landing tiles and prefer pad. I'll accumulate: `if(!landed || c==='P') landed = {...}`.

Also crumbling trigger: trigger on any contact with an X block (landing on top). ✓

Also: should a crumbling block trigger when the ball merely touches its side? Spec says "after the ball first lands on it" → top landing ✓.

Now, one problem: when the ball is resting on an X block, each step produces a landing → triggerCrumble repeatedly. I'll only trigger if state==='idle' ✓.

Crumble update:
```js
for(const cr of crumbles){
  if(cr.state==='shake'){ cr.t-=dt; if(cr.t<=0){ cr.state='gone'; cr.t=CRUMBLE_REGEN; puffParticles(cr);} }
  else if(cr.state==='gone'){ cr.t-=dt; if(cr.t<=0){ cr.state='idle'; } }
}
```
triggerCrumble: cr.state='shake'; cr.t=0.5.

CRUMBLE_SHAKE = 0.5, CRUMBLE_REGEN = 3.0.

Now pickups:
```js
function checkPickups(){
  for(const h of level.hoops) if(!h.taken && dist(ball,h)<0.85){ h.taken=true; score+=100; fx... }
  for(const c of level.checks) if(!c.taken && dist(ball,c)<0.8){ c.taken=true; score+=200; activeCheck=c; clear previous active }
  ...
}
```
"becomes visibly active and clears the previous active checkpoint" → only one active at a time. So `c.active = true; others active=false`.

Respawn uses the latest active checkpoint (which is the active one) ✓.

Crystal: taken → score += 1000; lives = min(5, lives+1).

Exit: if doorOpen (hoopsRemaining===0) and overlap → level complete.

Death: spike check.

Spike lethal rect for tile (tx,ty): x [tx+0.22, tx+0.78], y [ty+0.5, ty+1]. Circle-rect distance < R.

Let me write `spikeHit()`: iterate over tiles overlapping the ball's bbox; if '^' → test.

Now the exit overlap: door rect x [ex, ex+1], y [ey, ey+2] where ey = exit bottom row - 1 (top). Let me store exit as {x: col, yTop: row of D, yBot: row of E}. Rect = [x, x+1] × [yTop, yBot+1).

Circle-rect distance < R → complete.

Now the state machine and rendering.

Let me write the code.

For particles: array of {x,y,vx,vy,life,max,color,size}.

Death burst: 12 fragments, speed 3-7 t/s, life 0.4 s.

Also small "pop" particles when collecting a hoop? Not required; "Add only two ball effects: a small squash/stretch based on impacts and speed, and a roughly 0.4-second expanding-fragment burst on death." So only those two effects. I'll avoid extra particle effects to comply. Hmm, crumbling blocks need "a visible tell" — that's the shaking, not a ball effect. I'll show cracks + jitter, and when gone, draw nothing (or a faint outline). That's fine — the restriction is about ball effects.

Actually "Effects must not alter collision geometry" — fine.

Let me keep particles only for death. For crumble collapse, I'll show the block fading/jittering (a tile effect, allowed). I'll add a small debris animation for the crumble? The spec says "Add only two ball effects" — that's about ball effects specifically. A crumbling block's collapse tell is a block effect. I'll keep it simple: shaking offset + cracks, then gone (draw a faint dashed outline).

Now rendering.

```js
function render(){
  ctx.setTransform(SCALE,0,0,SCALE,0,0);
  // bg
  ctx.fillStyle = pal.bg; ctx.fillRect(0,0,LOGICAL,LOGICAL);
  // subtle bg grid / bgAlt stripes for depth? keep flat.
  const camPx = Math.round(cam*8);
  const t0 = Math.floor(camPx/8)-1, t1 = t0+VIEW+2;
  ...
}
```

Draw order: bg, tiles, objects, door, ball, particles.

Tile drawing: for ty 0..15, tx t0..t1: if in bounds and solid → fill. Also draw spikes, pads, crumbles.

For solid tiles, draw the block fill; then if the tile above is not solid, draw a 1-logical-px top highlight in blockTop.

Also draw a 1px darker outline? "at most a one-logical-pixel outline" ✓.

Spikes: draw triangles. For a spike tile at (tx,ty): draw 3 triangles pointing up, base at the tile bottom.

Pads: draw the tile as a dark base block, then a lime band at the top 3 logical px, plus two small chevrons.

Crumble: draw the block in crumble color with 2-3 crack lines (dark 1px). If shaking, offset x by ±1 px (deterministic jitter based on time). If gone, draw a 1px dashed outline in a dim color.

Hoop: ring. Draw with ctx.arc, lineWidth 1.5, radius 2.6 logical px, centered at (cx, cy). Add a small inner? Keep it a clean ring. Also draw collected hoops as nothing.

Checkpoint: a diamond outline when inactive; when active, a filled diamond + a 1px vertical post going down. Let me draw: a post from the tile bottom up 6 px and a triangle flag. Hmm, "Checkpoint: collected on overlap. It awards 200 points once, becomes visibly active". A flag reads well. Let me draw a small flag: vertical line at cx from cy-3 to cy+4, and a triangle to the right at the top. Inactive = dim color, active = bright.

Crystal: filled circle radius 2.6 with a lighter inner circle radius 1.2, plus a 1px outline.

Exit door: 2 tiles tall at (ex, ey..ey+1). Closed: fill with doorClosed color, draw a 1px outline and a horizontal bar across the middle plus a diagonal hatch. Open: draw the frame outline (1px) in doorOpen color and a thin inner glow line; also draw two small posts.

Ball: circle radius 4 logical px with squash/stretch. Draw fill red, 1px darker outline. Add a small dark "shadow" arc? Keep flat.

Also draw a subtle ground shadow? No.

Death: hide the ball, draw fragments.

HUD update in render.

Overlay: HTML.

Let me write the code now.

Camera update in step:
```js
const target = clamp(ball.x - VIEW/2, 0, level.w - VIEW);
cam += (target - cam) * (1 - Math.exp(-dt/0.16));
```

Now the main loop and state machine.

States: 'title','play','dying','levelclear','gameover','complete'.

Title: render a title screen? The spec says the title screen contains only the game name, "Press Space to Start" and a one-line control hint. I'll render the overlay HTML over a static background (maybe the level 1 map preview, or just a flat bg). Simplest: draw a flat background with the level-1 palette and show the HTML card. Actually "The title screen contains only..." — so no world rendering needed. I'll draw a plain dark background with a few decorative blocks? No — keep it minimal: flat background. Hmm, but the canvas would be empty. I think showing the title as an HTML overlay over a flat dark canvas is fine and matches "contains only".

Let me draw a subtle static scene: the level 1 map without objects? That might count as extra content. I'll keep the canvas flat dark with just the game name in the overlay. Actually, to make it look nice, I'll render a simple decorative pattern of blocks in the canvas for the title... risky re "contains only the game name...". I'll keep the canvas plain (single solid color) — clean and compliant.

Hmm, a completely empty 512x512 dark square with text is fine and stylish.

Let me instead render the title with the ball icon? No. Keep it plain.

Level complete card: "LEVEL 1 COMPLETE" + "SCORE 00000750" + "Press Space".

Game over: "GAME OVER" + score; auto-return to title after 1.8 s.

Game complete: "GAME COMPLETE" + final score.

Now, HUD during title: show lives/level/hoops/score? It's fine to show the HUD always. During title, lives=3, level 1, hoops 6, score 00000000.

Let me write the code.

One more: "Prevent those keys from scrolling the page while the game has focus." I'll add keydown on window and preventDefault for the game keys.

Let me write game.js now.

I'll write it in chunks. Chunk 1.

Also need to handle: when the level starts, reset crumbles, hoops, checkpoints, crystal, doorOpen.

Let me write.

Also: `resetRun()` → lives=3, score=0, levelIndex=0, startLevel(0).

`startLevel(i)` → parse level i fresh (deep copy grid), reset objects, place ball at spawn, cam = clamp, state='play'.

Death → respawn: ball at respawn point, vx=vy=0, grounded=false, squash=0.

Let me write the code.

Regarding the fixed timestep and the dying timer: I'll advance the death timer inside step() so it's frame-rate independent ✓.

Let me write chunk 1 now.

For validation at load, I'll run a check function and console.log warnings.

Let me write.

Also I want a headless sanity test: I can write a small test harness that loads game.js in Node with stubs? That's complex. Instead, I'll write a separate test script that re-implements the physics constants and simulates a simple bot per level to check reachability... That's a lot. 

Alternative: I can extract the physics into a testable form by making game.js work in Node if `typeof window === 'undefined'` — guard the DOM parts. Then write a test script that requires game.js and runs a scripted input bot. That's valuable for verifying completability.

Let me structure game.js so that DOM access happens only inside an `init()` called at the end guarded by `if (typeof document !== 'undefined')`. And export functions via `if (typeof module !== 'undefined') module.exports = {...}`.

Then a test file `test.js` can require game.js, set up a level, and drive inputs with a simple AI: hold right always, hold bounce when needed... A simple bot: hold right; hold bounce when the tile ahead-below is a spike or when blocked. That could verify traversal. Let me write a reasonably smart bot:

Bot policy: 
- Always hold right.
- Hold bounce if: grounded AND (the tile at (x+1..x+2, row below) is not solid) OR blocked by a wall ahead (vx≈0 and solid ahead) OR the tile ahead at ball row is solid.
This is a classic simple platformer bot. Let me implement and see if it clears all 4 levels. That would strongly validate completability.

I'll do that after writing game.js. Good idea.

Let me write game.js with a clean separation:

```js
const API = { LEVELS, parseLevel, loadLevel, stepPhysics, keys, ball, state, ... };
```

Let me write it.

I need to be careful that the bot test doesn't require rendering.

Let me write game.js now.

Structure:

```js
'use strict';
const TILE=8, VIEW=16, LOGICAL=128, SCALE=4;
... constants ...
const LEVELS=[...];
// ---- mutable game state
let level=null, ball={...}, cam=0, keys={left:false,right:false,bounce:false}, ...
function parseLevel(def){...}
function loadLevel(i){...}
function isSolid(x,y){...}
...
function physicsStep(dt){...}   // pure sim + pickups + death detection, returns event
function update(dt){ ... state machine ... }
// rendering
function render(){...}
// DOM
if (typeof document!=='undefined') { ...boot... }
if (typeof module!=='undefined' && module.exports) module.exports = {...};
```

Let me write it.

For the bot test I need `physicsStep` to not depend on DOM ✓.

Let me write chunk 1 (constants + levels + palettes + parse).

Then chunk 2 (state + physics).
Then chunk 3 (render + HUD + loop + boot).

Writing now.

Now chunk 2: state, physics, collisions, pickups, state machine.

Let me append with edit (append to the end). I'll use bash `cat >>`? No — better to use the edit tool with an anchor at the end, or just write a second file... Actually the guideline says write in chunks with write then append with edit. I'll use edit with oldText = the last lines of the file.

Let me append.

Now chunk 3: rendering, HUD, overlays, input, main loop, boot, and module exports for testing.

Let me write the rendering.

Canvas setup: `const canvas = document.getElementById('game'); canvas.width = CANVAS; canvas.height = CANVAS;`

Render function:

```js
function render(){
  ctx.setTransform(SCALE,0,0,SCALE,0,0);
  const l = run.level;
  const pal = l ? l.pal : LEVELS[0].pal;
  ctx.fillStyle = pal.bg; ctx.fillRect(0,0,LOGICAL,LOGICAL);
  if (run.state === 'title'){ ... nothing else ... }
  else { drawWorld(pal); }
  updateHUD();
  updateOverlay();
}
```

drawWorld:
- camPx = Math.round(run.cam * TILE)
- background far pattern: draw a few vertical bands / a horizon line in bgFar for depth. Let's draw a simple band: for each column, a dim rectangle at rows 12-13? Hmm, keep it flat: draw a dim horizontal band in bgFar across the bottom rows behind the blocks? Since the floor covers rows 14-15 mostly, a band behind at rows 11-13 would show. Let me draw a subtle "far" band: fillRect(0, 11*8, LOGICAL, 3*8) in bgFar — a horizon strip. That's flat and geometric, gives depth without gradients. But it moves with the camera? It's a horizontal band, so it doesn't need to move ✓ no jitter.

Actually a static band could look odd when the camera moves. It's fine — it reads as a distant horizon.

Hmm, but for level 4 with a plateau at rows 9-14, the band would be behind it. Fine.

Let me instead add a subtle parallax: draw dim vertical pillars in bgFar at fixed world positions (every 8 tiles, a 2-tile-wide column from row 8 to 14). That gives a sense of motion. It's flat geometric, no gradients. Let's do that — it's decorative background, not a map row obstruction. It's drawn behind everything.

Hmm, "Make the world flat, geometric, high-contrast and readable" — a dim parallax layer is fine.

I'll draw: for each tile column tx in view, if (tx % 7 === 0) draw a rect in bgFar from row 6 to row 14, width 2 tiles. Offset by camPx*0.5 for parallax? Parallax with rounding could cause jitter. Let me use parallax factor 0.5 and round to integer logical px — fine.

Actually simpler and safest: no parallax, just a dim horizon band. Let me do dim vertical bars anchored to the world (no parallax) — they move exactly with the camera, crisp. Good.

Let me draw them at world columns where (tx % 8) === 3, spanning rows 5..13, width 2 tiles, color bgFar. That gives a nice "place" feel.

Then tiles.

Tile drawing:
```js
for (ty 0..15) for (tx = t0..t1) {
  const c = tileAt(tx,ty);
  const px = tx*TILE - camPx, py = ty*TILE;
  if (c==='#') drawBlock(px,py,pal);
  else if (c==='X') drawCrumble(...)
  else if (c==='P') drawPad(...)
  else if (c==='^') drawSpike(...)
}
```

drawBlock: fillStyle block; fillRect(px,py,8,8); if !isSolid(tx,ty-1) → fillStyle blockTop; fillRect(px,py,8,1).

Also to make blocks read as separate tiles, draw a 1px darker line at the left edge? Keep it simple: top highlight only.

drawSpike: three triangles. Base at py+8. Triangles: for i in 0..2: x0 = px + i*2.67, width 2.67. Let me draw 3 triangles each 2.667 wide: apex at (x+1.33, py+1), base (x, py+8) to (x+2.667, py+8). Fill spike color.

Actually let me draw 3 spikes of width 8/3 ≈ 2.67. Use path.

drawPad: fill padBase rect (8x8), then top band padTop fillRect(px,py,8,3), then two chevrons: small triangles in a darker green? Let's draw two 1px chevrons in padBase over the band. Simple: fillRect(px+1,py+1,2,1) and fillRect(px+5,py+1,2,1) in padBase? Hmm. Let me draw the band with two notches.

drawCrumble: fill crumble color rect; draw crack lines in COL.crack (1px): a zigzag. If state==='tell', jitter offset = ±1 px based on Math.floor(time*30)%2, and draw brighter cracks. If 'gone', draw a 1px outline rect in COL.gone (dashed-ish) — I'll draw just corner marks.

Objects:
- Hoop: ring at (h.x*TILE - camPx, h.y*TILE). ctx.arc(cx,cy,2.6,0,2π), lineWidth 1.6, strokeStyle hoop.
- Checkpoint: post + flag.
- Crystal: circle.
- Door: at exit.

Door drawing:
```
const e = l.exit; const px = e.tx*TILE - camPx, py = e.tyTop*TILE;
if closed: fill doorClosed rect(px,py,8,16); outline 1px doorBar; bar: fillRect(px+1, py+7, 6, 2) doorBar; plus two vertical lines.
if open: stroke rect(px+0.5, py+0.5, 7, 15) doorOpen lineWidth 1; plus inner top-left corner marks; plus a bright inner rect fillRect(px+2,py+2,4,12) with a dim version? 
```
Let me make open door: draw a 1px outline in doorOpen and a filled "light" column: fillRect(px+3, py+2, 2, 12) in doorOpen with low alpha? No gradients/alpha... alpha is fine (solid fill with alpha is still a solid fill). I'll use a dim color instead: '#3a4a52'. Hmm, per-level. Let me just draw the outline plus two short horizontal ticks. Good enough — visibly open (no slab).

Ball: 
```
const bx = ball.x*TILE - camPx, by = ball.y*TILE;
const s = ball.squash - ball.stretch; // >0 flat, <1? 
rx = R*TILE*(1+s), ry = R*TILE*(1-s)
```
where s in [-0.28, 0.45].

Draw ellipse via ctx.ellipse.

Add a 1px outline: strokeStyle ballEdge lineWidth 1.

Also draw a small dark "eye"/marker? Not needed. Red circle is distinctive.

Fragments: small squares in ball color.

Screen shake: if run.shake>0, offset the whole transform by ±1 px. Hmm, "The camera must not visibly jitter" — that's about the camera following. A death shake is a deliberate effect but might conflict. I'll skip the shake to be safe. Let me remove run.shake usage in rendering (keep the variable but don't apply). Actually let me just not use it at all. I'll leave the variable but not apply any offset. Better: remove shake entirely to avoid violating "camera must not visibly jitter". I'll keep the field but never offset the camera. Fine — I'll just not use it in render.

HUD: update DOM.

Overlay: build HTML for cards.

Input: keydown/keyup.

Main loop with accumulator.

Let me write it.

Also the "hoops remaining" display.

Let me write the overlay HTML structure:

```html
<div id="overlay"><div class="card">...</div></div>
```

I'll set innerHTML when the state changes (track lastOverlay string).

Card contents:
- title: `<h1>BOUNCE</h1><p class="press">Press Space to Start</p><p class="hint">← / A roll left · → / D roll right · ↑ / W / Space bounce</p>`
- levelclear: `<h2>LEVEL n COMPLETE</h2><p>SCORE 00000750</p><p class="press">Press Space</p>`
- gameover: `<h2>GAME OVER</h2><p>SCORE ...</p>` (auto)
- complete: `<h1>GAME COMPLETE</h1><p>FINAL SCORE ...</p><p class="press">Press Space</p>`

Space handling: on keydown Space:
- title → startRun()
- levelclear → loadLevel(next); state='play'
- complete → state='title'
- gameover → nothing (auto after 2 s) — but allow Space to skip? Spec: "show Game Over briefly, then return to the title screen". I'll let Space skip after 0.6 s. Simpler: ignore Space during gameover; auto after 2 s.
- play → bounce (it's a held key).

Note: Space is both bounce and advance. When a level completes and the player is holding space... The transition happens on keydown edge, so holding space from the level won't retrigger ✓ (I'll track key edges).

Let me implement: in keydown, if e.repeat return.

Now write chunk 3.

For the HUD lives: build 5 spans; toggle class 'on'.

Let me write.

Also: canvas focus — the game listens on window, so no focus needed. "while the game has focus" — I'll just always preventDefault for those keys.

Let me write the code.

One more: the render must handle run.state==='title' where run.level may be null (before any run). I'll load level 0 data at boot for the palette but not render the world. Actually at boot, run.level = null. Let me set run.level = parseLevel(LEVELS[0]) at boot so the HUD shows level 1 / hoops 6. Hmm, but then the HUD shows real values. Fine.

Actually simpler: at boot call `loadLevel(0)` and set state='title'. Then the world isn't drawn during title. HUD shows lives 3, level 1, hoops 6, score 00000000 ✓.

But loadLevel places the ball and sets cam — fine.

Let me write.

For the test harness, export an object with the needed internals.

Let me write chunk 3 now.

Now index.html and style.css.

Note: in `advance()` for 'complete' → I set state='title' and loadLevel(0) and reset lives/score. Good — "return to the title screen with a completely fresh run".

Also for gameover → auto to title after 2 s, but the run state (lives=0, level, score) persists until the player presses Space at the title (startRun resets). At the title screen, HUD shows lives 0... Hmm, that's odd. Let me reset on entering title from gameover: in update(), when gameover timer expires → run.state='title'; and reset run (lives=3, score=0, loadLevel(0)). Let me add that.

Let me edit update().

Also `run.shake` is unused in render — fine, but let me remove it to keep things clean. Actually it's referenced in update (decrement) and set on death. Harmless. I'll leave it but it's dead weight. Let me remove it for cleanliness.

Let me make those edits.

Also: `performance.now()` used in drawCrumble — fine in browser.

Now index.html + style.css.

The first edit was a no-op (identical old/new) — that may have caused an issue? Actually the error is about edits[1]. Let me look at the actual text in the file.

Also edits[2] references `advance()`'s complete branch. Let me read the relevant part of the file.

The whole edit call failed (atomic). Let me redo with correct text. Let me read lines 470-490 and 710-725.

Now I see the exact text. The issue was edits[1] oldText had `  }\n}` at the end but the actual has `  }\n  if (run.shake > 0) run.shake -= dt;\n}`. Let me redo.

Also remove run.shake entirely.

`freshTitle` is used in `update()` before its definition — function declarations are hoisted ✓. But `advance()` also uses `freshTitle` ✓ hoisted.

Now index.html and style.css.

Now style.css. The canvas is 512x512 internal, displayed at 512x512 (crisp, 1:1). Actually to "scale up crisply to suit a desktop browser", 512 is good. Let me set CSS width/height to 512px and image-rendering: pixelated (harmless since 1:1).

Hmm — maybe scale to 560? Keep 512 exactly for 1:1 crispness.

HUD bar below: fixed width matching the canvas (512px), flex layout: lives left, level, hoops, score right-aligned.

Overlay: absolutely positioned over the canvas, centered text.

Let me write.

Now let me write a headless test harness that plays each level with a bot, to verify completability and the physics properties.

Test plan:
1. Load game.js in Node (module.exports present). But game.js references `performance.now()` in drawCrumble (only in render, not called) ✓. And `document` guarded ✓. And `requestAnimationFrame` guarded ✓.

2. Bot: simulate fixed steps; set keys each step based on a policy.

Bot policy (simple but reasonable):
- Always hold right.
- Hold bounce if:
  - grounded AND the tile below-ahead is not solid (gap/spike ahead) → bounce
  - OR blocked: vx == 0 and there's a solid tile at ball row ahead → bounce
  - OR the tile directly ahead at the ball's row is solid → bounce (wall)
- Additionally, for the pad→high-ledge jumps, holding right + bounce continuously would... hmm. Holding bounce continuously makes the ball bounce every landing at full height. That's actually a decent strategy: hold right + hold bounce → continuous max-height hops at max speed. Would that clear all levels? Let's test: "hold right and hold bounce always".

Level 1: continuous hops of 3 tiles height, ~6.2 tiles length at max speed. Spikes at 16-17 ✓ cleared. Step at cols 25-28 (top y=12): the ball hops along; when it hits the step's wall it slides up and lands on top ✓ maybe. Then it needs to drop off... continuous hopping might overshoot into spikes at 38-39? It would clear them (6.2 tile hops) ✓. Exit at 49 ✓.

Hmm, but continuous hopping might land on the shelf or miss hoops? Hoops are collected on overlap during flight too ✓ (the ball passes through row 13 near the ground... actually with continuous 3-tile hops, the ball's center oscillates between 13.5 and 10.5; hoops at row 13 (center 13.5) are collected when the ball is near the ground ✓ within 0.85 distance).

Let me just test several bot policies and see if any completes all 4 levels:
A) hold right only.
B) hold right + hold bounce always.
C) adaptive: hold right; hold bounce when needed.

Let me write the test with policy C primarily, and also check A/B.

Policy C details:
```
function think(){
  keys.right = true; keys.left = false;
  const b = ball;
  const fx = Math.floor(b.x), fy = Math.floor(b.y);
  // look ahead
  const aheadTile = Math.floor(b.x + 0.6);
  const groundAhead = isSolid(Math.floor(b.x + 0.8), Math.floor(b.y + 0.6)); // support ahead
  const wallAhead = isSolid(Math.floor(b.x + 0.6), Math.floor(b.y)) || isSolid(Math.floor(b.x+0.6), Math.floor(b.y - 0.4));
  const spikeAhead = tileAt(...) === '^' within 1.5 tiles
  ...
}
```

Let me define:
- `supportAhead`: is there solid ground at (floor(b.x + 1.0), floor(b.y + 0.5))? The ball's bottom is at b.y+0.5; the tile below is row floor(b.y+0.5+ε). Looking 1 tile ahead.
- If grounded and !supportAhead → need to bounce.
- If wallAhead (solid at row floor(b.y) at x+0.7) → bounce.
- Also if a spike tile is within 1.2 tiles ahead in the ball's row or the row below → bounce.

Also for the pad→high jump: the pad launches automatically ✓ no bounce needed. But the ball must have speed ≥ ~4.5 → holding right gives max speed ✓.

For the crystal detours, the bot won't get them — that's fine (optional). But I want to verify the crystal is reachable. I can write a targeted test for each crystal: place the ball at a specific spot and run a scripted input to collect it.

Let me first test the critical path.

Also I need to verify: "each of the four levels has exactly 6 hoops ... and its exit stays shut until its own hoop counter reaches 0" — the bot test will confirm the exit opens.

Let me write test.js.

Important: game.js's `update()` handles the state machine; I'll drive `update(DT)` repeatedly and check state transitions. Set run.state='play' and loadLevel(i).

Also the bot must handle crumbling block crossings: hold right at max speed ✓.

Let me write it.

Potential issue: the bot's "bounce when no support ahead" may cause it to bounce too early/late. Let's iterate.

Let me write test.js.

Also add physics property tests:
- Bounce height from standing vs at full speed: measure apex height.
- Pad height = 6.
- Speed doesn't change height.
- Frame-rate independence: run the same input at different "frame rates" — but since physics is fixed-step, it's identical by construction. I can test by calling update(DT) N times vs. simulating an accumulator... The accumulator lives in `frame()` which needs rAF. I'll just assert the fixed step is used. I can test determinism: run the same input sequence twice → identical results.

Let me write the tests.

For measuring bounce height: place the ball on flat ground in level 1 (x=5.5, y=13.5), set keys.bounce=true, run steps, record min y (apex). Compare with 13.5 - 3 = 10.5.

With speed: give vx=6 first, then bounce; measure apex.

Let me write.

Also test that a normal bounce clears a 2-tile ledge and that a 4-tile wall is not clearable without a pad.

Let me write test.js now.

game.js has `if (typeof document !== 'undefined')` guard — in Node, document is undefined ✓. But `performance` is a global in Node 16+ ✓ (used only in render).

Let me run the test.

There's a parent package.json with "type":"module". I'll rename test.js to test.cjs and use a copy of game.js as .cjs? Better: create a local package.json in the working dir without "type":"module"? That would override. But adding a package.json might be considered a "package manager" artifact — it's just a marker. Hmm, the constraint says "no package manager". A package.json with just `{"type":"commonjs"}` is harmless but might look odd.

Alternative: run the test with `node --experimental-...`? Simpler: make test.cjs and load game.js via dynamic import? game.js uses `module.exports` guarded by `typeof module !== 'undefined'` — in ESM, `module` is undefined, so the export block is skipped. I could instead use `import()` and have game.js attach to globalThis.

Cleanest: in game.js, add `if (typeof globalThis !== 'undefined' && typeof module === 'undefined') globalThis.BOUNCE = {...}` — but in a browser `module` is undefined too, so it would also set globalThis.BOUNCE in the browser. That's harmless.

Simplest approach: create a local `package.json` with `{"type":"commonjs"}`. Hmm, but the task says no package manager — a package.json isn't using a package manager, but it could confuse the static host? It's static hosting; package.json is ignored. Still, I'd rather avoid extra files.

Better: copy game.js to a temp .cjs for testing. E.g., `cp game.js /tmp/game.cjs && cp test.js /tmp/test.cjs` — but test.js requires './game.js'. I can make test.cjs require a path. Let me just do the test in /tmp: copy game.js → /tmp/bounce/game.cjs and test.js → /tmp/bounce/test.cjs with require('./game.cjs').

Let me do that: sed the require path.

Actually simplest: in test.js use `require('./game.js')` but run node with `--input-type=commonjs`? For files, node decides by package.json. I can create /tmp/bounce/package.json with {"type":"commonjs"} and copy both files there. Let's do that.

parseLevel returns `out` without `map`. Let me add `map: def.map` to the parsed level. Fix in game.js.

Also `run.level.grid.join('')` — grid is an array of arrays; join flattens arrays to strings ✓ works.

Let me re-run.

Good progress. Let me debug each failure.

1. "L3 pads only from L2" — my test logic: `(countP===0) === (i===0)`. For L3 (i=2), countP should be >0? No — L3 has no pads, so countP===0 is true, and (i===0) is false → mismatch. My test assertion is wrong: pads must not appear in L1 only. Let me fix the test: pads must be 0 in L1, >0 in L2 and L4, and L3 may have 0. Fix: `ok('L'+..+' pads absent in L1 / present in L2 & L4', (i===0 ? countP===0 : (i===1||i===3) ? countP>0 : true))`.

2. Pad launch test: I set `run.level.grid[14][Math.floor(ball.x)] = 'P'` but ball.x is set AFTER loadLevel... In apexHeight I call loadLevel(0) first, which places the ball at spawn (2.5, 13.5). Then I set grid[14][2]='P'. Then I set ball.x=6.5 — so the pad is at col 2, not under the ball. Fix: set the pad at col 6.

3. "2-tile wall cleared from standing": my test builds a wall at cols 10-13 rows 12,13 and starts the ball at x=8.5 on the ground, holding left+right? I used hold(true,false,true) = left=true, right=false, bounce=true. Oops — hold(l,r,b) with l=true means left. I wanted right. Actually the wall is to the right (cols 10-13) and the ball at 8.5 → needs to move right. I passed left=true. Fix: hold(false,true,true).

Hmm wait, but actually the ball at 8.5 with the wall at cols 10-13... the ball rolls right, hits the wall at col 10 (x=10..11) at center 9.5, bounces, climbs. Should work.

4. Bot playthrough failures — need to debug. Let me instrument: print where the bot gets stuck.

5. Crystal tests: my scripted route is crude. Let me improve: place the ball at the ledge edge, then run a scripted sequence: hold bounce continuously and hold right. Let me debug.

6. "closed door is impassable": I placed the ball at (e.tx+0.5, e.tyBot+0.5) = (49.5, 13.5) — inside the door cell. The door is solid, so the ball starts inside a solid tile. collideX: for tile (49,13): dy = 0 → h=0.5 → forbidden [48.5, 50.5]; ball x=49.5 inside; vx=0 → leftAmt = 1.0, rightAmt = 1.0 → not <, so b.x = hi = 50.5. So it got pushed right (to the far side) rather than left. My assertion `ball.x < e.tx` fails. That's an artifact of starting inside a solid. Let me instead place the ball at 48.5 approaching with vx=+3 and check it stops and doesn't pass.

Let me fix the tests and then debug the bot.

Let me first fix the test issues, then investigate the bot.

For the bot, let me add a debug trace: print the ball position over time for level 1 to see where it stalls.

Let me think about what could stall. Level 1: the bot holds right always and bounces when needed. Hoops collected: 1 of 6 (5 remaining) → the bot collected only 1 hoop?! That means it's stuck early. Actually "hoops=5" means 1 collected. Hmm, with continuous hopping it might skip hoops? Hoop collection radius 0.85 — a hopping ball passes over a hoop at row 13 only when near the ground.

Wait, the bot only bounces when needed, so it rolls along the ground collecting ground hoops. Level 1 hoops: 6, 11, 21, 27(step top), 36, 47. If it collected only 1, it's stuck around col 11-21.

Possibly stuck at the step at cols 25-28? Or stuck at the spikes at 16-17: the bot bounces when a spike is ahead, but maybe it bounces too late and dies... deaths=0 though. So it's not dying. It's stuck.

Hmm, "hoops=5" — maybe it's stuck against the step wall at col 25. Let me trace.

Let me write a debug script.

Actually, let me reconsider the bot's "wall ahead → hop" logic: `isSolid(Math.floor(b.x+0.7), rowMid)`. When the ball is on the ground at center y=13.5, rowMid = 13. The step occupies rows 12,13 → at col 25, row 13 is solid ✓ detected. So it bounces. But it keeps holding right, so it accelerates into the wall, vx zeroed, and it bounces... Each landing: keys.bounce true → vy = -V_BOUNCE ✓. It rises. While rising, `b.grounded` is false, and the "wall ahead" check still true → bounce stays true (irrelevant in the air). It should rise 3 tiles and then be above the step top (y=12): the ball's center must be < 11.5 to clear. Apex 10.5 ✓. During the rise, holding right accelerates it at air control 7.2 → it should move right onto the step.

Hmm, but the collision: while rising against the wall, the ball is pushed to x=24.5 each step. Once its center y < 11.5 - ... let's see: the wall tile at (25,13) spans y [13,14). Ball center y: when y+0.5 < 13 → y < 12.5, no overlap with row 13 tile. But the tile at (25,12) spans [12,13): overlap while y+0.5 > 12 → y < 12.5. So the ball is blocked until y < 11.5. Apex 10.5 ✓ so it clears.

But: the ball's vy is reset to 0 on each landing, and the landing happens every step while grounded. With bounce held, vy = -11.489 each landing. So it leaves the ground immediately ✓.

Hmm, so why stuck? Let me actually trace.

Another possibility: the bot's `if(b.grounded && Math.abs(b.vx) < 0.2) need = true;` — fine.

Let me just trace level 1 with the bot and print positions every 0.5 s.

Let me write a debug script.

The bot works well but overshoots: it climbs the step, then keeps bouncing and ends up past the exit at the right wall (x=51.5, level width 52 → out-of-bounds solid at col 52). Hoop 36 was missed because it was bouncing over it at height.

So the bot's issue: it bounces too much and misses ground hoops, and it hits the right wall. The exit door at col 49 was closed (hoop 36 not collected) so it stopped at the wall.

The bot needs to collect all 6 hoops. A human player would collect them. So the bot policy needs improvement: it should stay on the ground when a hoop is ahead at ground level.

Let me improve the bot: if there's an uncollected hoop within ~3 tiles ahead and it's at roughly the ball's row (ground level), don't bounce unless forced (hazard immediately ahead).

Better approach: make the bot smarter — a small lookahead search? That's heavy. Let me instead tune the policy:

- Compute hazard: is there a spike or missing support within 1.5 tiles ahead at the ball's row/below? If yes → must bounce.
- Wall ahead → bounce.
- Otherwise, if an uncollected hoop is ahead within 4 tiles and roughly at ground level (hoop.y within 1 of ball.y) → don't bounce (roll to it).
- Also if the ball is grounded and there's a hoop ahead that requires climbing (hoop.y < ball.y - 1) → bounce.

Also the bot should stop at the exit... it will touch it when open.

Also, the bot overshooting the level end: it hits the right wall and gets stuck. With all hoops collected the door opens → it enters ✓.

Let me also handle: after climbing the step, hoop 27 at (27,11) was collected ✓. Hoop 36 at row 13 was missed because the ball was airborne over it.

Let me refine: when grounded and no hazard within 2.5 tiles ahead, don't bounce (roll). When airborne, keep bounce held only if needed for the next obstacle.

Actually the key issue: the bot bounces at the spikes at 16-17, lands at ~21, then at 24 it hits the step wall and climbs, then keeps bouncing (because "no support ahead" triggers when it runs off the step at col 28 → it bounces, and then keeps bouncing every landing since... hmm, after landing on flat ground at col 34ish, is there "no support ahead"? No. So why did it keep bouncing from 5.25 onward?

Looking at the trace: at 5.00 x=26.85 y=11.40 (on the step), 5.25 x=28.34 y=9.77 airborne vy=-7.46 → it bounced at the step edge because "no support ahead" (col 29 row 13 is empty → the ball's rowBelow = floor(11.4+0.55)=11... hmm.

Wait at x=26.85, y=11.40: rowBelow = floor(11.95) = 11. Tiles at row 11 cols 27,28... The step is rows 12,13 at cols 25-28. So row 11 is empty → "no support ahead" → bounce. But the ball is airborne there (it was rising). The bounce key only matters at landing.

At 5.25 it's airborne rising. It then lands... at ~5.5 x=29.84 y=8.61 — it's still airborne and rising. Hmm, at 5.5 y=8.61 vy=-1.96 → apex ~8.5. So it launched from the step top with a full bounce ✓ (bounce held at landing). Then it flies 6+ tiles and lands around x=34-35 at ground level. Then at 6.25 x=34.34 y=8.00 vy=-8.10 → it bounced again immediately upon landing (bounce held because... at landing, was `need` true? At x≈33.5 landing, rowBelow = floor(13.5+0.55)=14, tiles ahead at cols 34,35,36 row 14 = '#' ✓ solid, no spikes. Wall ahead? rowMid=13, cols 34-35 row 13 = '.' ✓. So need=false → it should not bounce.

But the trace shows it bouncing. Hmm — because the check happens BEFORE update in my debug loop (think() then update). At the moment of think, the ball is airborne at y=8.0 → rowBelow = floor(8.55) = 8 → tiles at row 8 cols ahead are empty → "no support ahead" → need=true → bounce held → on landing it bounces. That's the bug: the lookahead uses the ball's current row while airborne.

Fix: only evaluate the "support ahead" test when grounded, and use the ground row (the row the ball would land on). Better: compute the lookahead from a "reference row" = the ball's grounded row. Let me define: find the ground level below the ball: scan down from ball.y to find the first solid tile; use that row+... Simpler: only apply the support/hazard lookahead when grounded; when airborne, look ahead at the row where the ball will land — approximate by scanning downward from the ball's position at x+d for the first solid tile and check if it's a spike.

Let me restructure the bot:

```
function think(){
  const b=ball;
  keys.left=false; keys.right=true;
  let need=false;
  // ground row under a future x position
  function groundRow(xf){
    for(let y=Math.floor(b.y-0.5); y<16; y++) if(isSolid(Math.floor(xf),y)) return y;
    return 16;
  }
  for(let d=0.7; d<=2.2; d+=0.5){
    const xf=b.x+d, tx=Math.floor(xf);
    const gr=groundRow(xf);
    if(gr>=16){ need=true; break; }              // bottomless (shouldn't happen)
    const c = run.level.grid[gr-1] ? run.level.grid[gr-1][tx] : '.';
    // the tile just above the ground surface: what will we roll onto?
    if(tileAt(tx,gr)==='^') need=true;
    // wall: solid at the rolling row (gr-1) ahead
    if(isSolid(tx,gr-1)) need=true;
  }
  ...
}
```

Hmm, this is getting complicated. Let me define it more simply:

The ball rolls on a surface. Let `surf` = the y of the surface the ball is currently on (or will land on). For lookahead, for each d, find the surface at x+d by scanning down from the ball's current bottom.

Actually simpler and effective: for lookahead distance d, scan the column at x+d from the ball's current y-1 downward to find the first solid tile at row `gr`. The "surface height" is `gr`. Then:
- If the tile at (tx, gr) is a spike → hazard → bounce.
- If the tile at (tx, gr-1) is solid → wall (the surface steps up by ≥1 tile at that column) → bounce.
- If no solid found within the level height → hole → bounce.

Also check spikes at (tx, gr-1) (a spike sitting on the surface).

Hmm, spikes are not solid, so scanning for solid tiles skips them. Let me scan for solid OR spike.

Let me define `blocked(tx,ty)` = isSolid or tileAt==='^'.

groundRow(xf): scan ty from floor(b.y - 0.5) to 15; return first ty where blocked(tx,ty) — that's the first obstacle row. Then:
- if tileAt(tx,ty)==='^' → hazard.
- else (solid) → check the tile above it (ty-1): if that's solid → step up → need bounce; if it's a spike → hazard at surface level → bounce.

Also the ball's own row: if the ball is at ground level and the tile at (tx, ty-1) is solid → wall ahead.

Let me just implement and iterate empirically.

Additionally, add hoop-seeking: if an uncollected hoop is ahead within 5 tiles and its y is >= ball.y - 0.6 (i.e., at or below the current surface), suppress bouncing unless a hazard is within 1.2 tiles.

Hmm, but the hoop at (27,11) is above the ground; the bot climbs the step because of the wall → collects it ✓.

Let me also handle the pads: the bot should hold right at max speed ✓ automatic.

Let me also handle the crumbling bridge: hold right ✓.

Let me rewrite think() and iterate.

Another thought: maybe a simpler and more robust bot: "always hold right; hold bounce if a hazard/wall is ahead within 2 tiles measured from the landing surface". Plus "don't bounce if an uncollected hoop is directly ahead on the ground within 3 tiles and no hazard within 1.5".

Let me implement and test.

Also, the level-4 pad→high-ledge jumps: the bot holds right (max speed) and lands on the pad → auto-launch ✓. But will the bot's "bounce" state matter? No, pads launch regardless ✓.

But careful: on the pad at cols 51-52 in L4, the bot's lookahead at d up to 2.2 → cols 53-54 are spikes → need=true → bounce held. It lands on the pad → pad launch (overrides) ✓.

Then in the air it flies over the spikes and lands on the crumbling bridge at col 57 ✓. Then it must keep moving right quickly (blocks collapse) ✓ holding right at 6 t/s ✓.

Let me now also consider L2's pad #2 → over the spike field: the bot lands on the pad at col 48 with speed 6 → flies 8.86 tiles → lands at 57.36 ✓.

OK let me rewrite the bot.

Also for the crystal tests, let me write a more careful scripted route. Actually, better: extend the bot to also attempt crystals by adding a rule: if the crystal is ahead and above, bounce when grounded near it. Hmm. Let me instead write a dedicated crystal test that uses the bot with an extra rule: when the crystal is within 6 tiles ahead and above the ball, hold bounce continuously (so it climbs). Let me try: place the bot on the step top at the right edge and hold bounce+right → it should hop onto the shelf.

Earlier analysis: from the step top at center 9.5 (L2/L3) or 28.5 (L1), holding bounce+right: the ball bounces at the step edge (it's grounded at the edge), rises 3 tiles, and moves right at air accel. It should land on the shelf ✓.

But in the test I placed the ball at (9.5, 11.5) with vx=0 and held right+bounce. Let me check why it failed. Possibly because the ball at x=9.5 is exactly at the step's right edge — is it supported? The step occupies cols 6-9 (x [6,10]). Ball center 9.5, spans [9,10] → supported by tile col 9 ✓. It bounces up 3 tiles, then accelerates right from 0: in 0.603 s above the shelf-top threshold... wait, the shelf for L2 is at cols 12-17 rows 10,11 (top y=10). The ball on the step top has center 11.5; to land on the shelf it must reach center 9.5 (rise 2). Air accel from vx=0: at t=0.221 (rise 2), x = 9.5 + 0.5*7.2*0.0489 = 9.5+0.176 = 9.68. At t=0.824 (rise 2 again, descending), x = 9.5 + 0.5*7.2*0.679 = 9.5+2.44 = 11.94. The shelf starts at col 12 (x [12,13]) → the ball center 11.94 spans [11.44,12.44] → overlaps col 12 ✓ lands on the shelf ✓.

Hmm, but wait: while airborne and moving right, the ball's apex is at rise 3 → center 8.5, and it lands on the shelf at rise 2 → center 9.5 ✓. So it should land at x≈11.94 on the shelf's left edge ✓. Then it rolls right along the shelf and collects the crystal at (14,9)... the ball on the shelf top (surface y=10) has center 9.5, and the crystal is at (14, 9.5) ✓ (crystal at row 9 → center y 9.5) ✓ distance 0 when x=14 ✓.

So why did the test fail? In my test I set `ball.y = 11.5` — wait, I passed sy=11.5 for L1/L2/L3 ✓ and for L4 sy=8.5 ✓. And `hold(false, r, b)` with r=true, b=true ✓. Then in the loop I set keys.bounce=true at k>60 — but `hold` already set it. Hmm, `hold(false, r, b)` sets keys.bounce = b = true ✓.

But `update(DT)` → physicsStep... the ball is grounded=true initially. First step: dir=+1 → vx += 7.2? No: grounded → ACC_G=18 → vx = 0.075. Then gravity, integrate, collideY → landing → bounce → vy = -11.489 ✓.

Then it rises. But `run.state` — I set run.state='play' ✓. Hmm, but `update` for state 'play' calls physicsStep ✓.

Wait — the crystal test loop: `if(k===60) keys.bounce = true; if(k>60) keys.bounce = true;` fine.

`if(run.level.crystal.taken){ got = true; break; }` — should trigger.

Hmm, maybe the ball falls off the step edge before bouncing? At x=9.5 with vx increasing, the ball is supported while center x ≤ 9.5+... For tile col 9 (x [9,10]): dx = distance from center x to [9,10]. At x=9.5, dx=0 → w=0.5 → support at y = 14-0.5 = 13.5? Wait the step surface: the step occupies rows 12,13 at cols 6-9. The ground row 14 is also solid. So the ball at center 11.5 — is it resting on the step top (y=12)? Yes, the tile at (9,12) spans y [12,13); the ball center 11.5 spans [11,12] → touching at 12. collideY: for tile (9,12): dx = 0 → w = 0.5 → forbidden [11.5, 13.5]; ball y=11.5 → `b.y > lo` → 11.5 > 11.5 false → no collision! Hmm. So at exactly y=11.5 there's no collision → not grounded → no bounce.

Then gravity pulls it down: y = 11.5 + tiny → collision → y = 11.5, landed ✓. OK it works on the next step.

Hmm, so it should work. Let me debug the crystal test directly.

Oh wait — I placed the ball at (9.5, 11.5) for L2, but for L2 the step is at cols 6-9 rows 12,13 ✓. And for L1 the step is at cols 25-28 → I passed sx=28.5 ✓. For L3 step cols 6-9 → 9.5 ✓. For L4 plateau cols 22-28 rows 9-14 → top y=9 → ball center 8.5 ✓ sx=28.5 ✓.

Let me debug the crystal route for L1.

Actually — potential problem: in the crystal test I call `reset(); loadLevel(i); run.state='play';` then set ball position. But `loadLevel` sets run.respawn etc. Fine.

Hmm, but `reset()` sets run.state='play' then loadLevel... fine.

Let me debug with prints.

Let me write a quick debug for crystal L1.

Interesting! The ball bounces at the step edge, rises, and at 0.88 it bounces AGAIN (vy=-10.30 at x=31.36, y=8.91) — meaning it landed on the shelf! Wait, at 0.75 y=9.11 (bottom 9.61) and the shelf top is y=10 → the ball's bottom at 9.61 is above 10 → it's above the shelf. Then at 0.88 vy=-10.30 → it landed and bounced. So it landed on the shelf at y=9.5 ✓ (center 9.5, bottom 10 = shelf top ✓).

Then it bounced again (bounce held) and flew off over the crystal at (32.5, 9.5)... At 0.88 x=31.36 y=8.91 — the crystal is at (32.5, 9.5). Distance = sqrt(1.14² + 0.59²) = 1.29 > 0.8 → not collected.

The problem: the ball landed on the shelf at x≈30.6-31 and immediately bounced (bounce held), flying over the crystal.

For L1 the ball landed on the shelf around x=30.6? At 0.75 x=30.63 y=9.11 — hmm, the shelf is at cols 31-34. At x=30.63 the ball center spans [30.13,31.13] → overlaps col 31 ✓ lands. Then bounces.

So the fix for the crystal test: don't hold bounce continuously; release bounce after landing on the shelf. A human would do that. Let me make the crystal test smarter: hold bounce until the ball lands on the shelf (detect grounded after being airborne), then release bounce and roll right.

Let me implement: hold bounce while airborne or until first landing after launch; then release.

Actually simpler: hold bounce only while the ball is above the launch surface... Let me do: `keys.bounce = true` until the ball becomes grounded again after having been airborne; then `keys.bounce = false`.

For L2 the ball landed on the shelf at x≈11.6-12.4 and bounced again, flying over the crystal at (14.5,9.5). Same fix.

For L1, the ball died at 2.13 (state=dying) — it flew off the shelf and hit spikes at 38-39? It was at x=38.86 y=13.05 → spikes at 38,39 ✓ died. Fine, that's after missing the crystal.

Let me fix the crystal test with the "bounce once then release" policy.

Now the main bot. Let me rewrite think() with a proper lookahead and hoop-seeking.

Let me design the bot more carefully:

```
function think(){
  const b = ball;
  keys.left = false; keys.right = true;
  const L = run.level;

  // surface row under the ball's current column (first blocked row at or below the ball's top)
  function scan(xf, fromY){
    for(let y=fromY; y<L.h; y++){
      const t = tileAt(Math.floor(xf), y);
      if(t==='#'||t==='P'||t==='X'||t==='^'||t==='E'||t==='D') return y;
    }
    return L.h;
  }
  const start = Math.floor(b.y - 0.5);
  const myRow = scan(b.x, start);      // surface row under the ball (solid row index)
  let hazard = false, wall = false, hole = false;
  for(let d=0.8; d<=2.4; d+=0.4){
    const xf = b.x + d;
    const r = scan(xf, start);
    if(r >= L.h){ hole = true; break; }
    const t = tileAt(Math.floor(xf), r);
    if(t==='^') hazard = true;
    // step up: solid occupying the row the ball would roll through
    if(r <= myRow - 1) wall = true;
    // spike sitting on the surface
    if(tileAt(Math.floor(xf), r-1)==='^') hazard = true;
  }
  ...
}
```

Hmm, `myRow` = the first blocked row at or below the ball's top. For a ball resting on the ground at center 13.5, top = 13.0 → start = 13. tileAt(x,13) = '.' → scan continues → y=14 → '#' → myRow = 14. Good.

For a lookahead column with a step (solid at rows 12,13,14): scan from 13 → y=13 is solid → r=13 → r <= myRow-1 = 13 → wall ✓.

For a spike patch at row 14: scan from 13 → y=14 is '^' → r=14, t='^' → hazard ✓.

For the shelf at rows 10,11 (cols 31-34) while the ball is on the ground (myRow=14): scan from start=13 at col 32 → y=13 '.', 14 '#' → r=14 → not a wall ✓ (the ball can roll under the shelf) ✓ good.

Now the hoop-seeking: find uncollected hoops ahead within 6 tiles. If a hoop's y is at the rolling level (hoop.y + 0.5 >= myRow - 1 ... let me define: the ball rolling on surface myRow has center y = myRow - 0.5. A hoop at (hx, hy) is "at rolling level" if |hy - (myRow-0.5)| <= 0.6. If such a hoop is ahead within 5 tiles and there's no hazard within 1.6 tiles → don't bounce.

Also: if the next hoop is above (requires climbing) → wall detection handles it.

Let me also handle the case where the ball is airborne: the lookahead from `start = floor(b.y-0.5)` while airborne high up would scan down and find the ground ✓ giving the landing surface ✓ good.

But `myRow` while airborne: e.g., the ball at y=8.5 → start = 8 → scan finds the ground at 14 → myRow=14 ✓. And lookahead columns with a step give r=13 → wall ✓. Good.

Now, the bounce decision: `need = hazard || wall || hole`. Plus if grounded and |vx| < 0.2 and there's an obstacle... keep.

Suppress: if a ground-level hoop is ahead within 4 tiles and no hazard within 1.8 → need = false.

Hmm, but the wall case: a hoop at ground level ahead with a wall between → we need the wall bounce. The suppression only applies when no hazard within 1.8; let me also require no wall within 1.8.

Let me define near = d <= 1.8 checks.

Let me restructure: compute `nearHazard` (d<=1.8) and `farHazard` (d<=2.4), `nearWall`, `farWall`.

need = farHazard || farWall || hole.
if (groundLevelHoopAhead within 5 && !nearHazard && !nearWall) need = false.

Let me implement and test.

Also the bot must handle the crumbling bridge: it holds right at speed 6 ✓.

And the pad jumps ✓.

One more: the bot should not bounce right before a pad (it would... actually bouncing before a pad is fine).

Let me also consider L4's high crumbling bridge at row 9 cols 56-59: after landing on it at col 57.7, the bot continues right ✓ to the solid block at 60-63 ✓, then across X at 64-65 ✓, then drops to the ground ✓, then to the exit ✓.

But: on the bridge, the bot's lookahead: myRow = 9 (surface row = 9, the X tile row). Wait: the ball on the bridge has center 8.5, top 8.0 → start = 8 → scan at col 57: y=8 '.'? The X is at row 9 → scan finds y=9 → myRow=9 ✓. Lookahead at col 60: rows 9-14 solid → scan from 8 → y=9 solid → r=9 → r <= myRow-1 = 8? No, 9 > 8 → not a wall ✓ continuous surface ✓.

Then at col 64 (X) ✓, col 66: ground row 14 → scan from 8 → y=8..13 empty, y=14 solid → r=14 → r <= 8? No → not a wall ✓ → the bot just runs off and drops ✓ good.

Now, when dropping from the bridge at col 66 to the ground, the lookahead while airborne: start = floor(8.5-0.5)=8 → at col 67 → r=14 ✓ fine.

OK. Also the drop from L2's plateau: fine.

Let me now also double check the bot doesn't die at L4's spikes at 53-55 (it takes the pad) ✓.

Let me write the improved bot in the test file and iterate.

Let me put the bot in a shared function in test.js.

Let me rewrite test.js's think() and the crystal tests, plus fix the other test bugs.

I'll iterate quickly using dbg.cjs with the new think.

Progress but issues:

Level 1: the bot loops — it reaches x≈38 and dies (spikes at 38-39), respawns at checkpoint 34, then re-runs and dies again. Hoop 36 remains. Hmm, it says "left=36,47" for a long time and deaths=26. It respawns at 14.5 → so the active checkpoint is 14, not 34! Because the bot bounced over checkpoint 34 (checkpoints are collected on overlap at ground level). So it respawns at 14 and has to redo.

Wait, at 113.50 x=14.53 → respawn at checkpoint 14. So checkpoint 34 was never collected. The bot was hopping (y ~9-11) over the checkpoint at (34,13.5).

Root cause: the bot hops too much, missing ground-level checkpoints and hoops.

Why is it hopping around x=34-38? Because of the spikes at 38-39 → it bounces early (lookahead 2.6 tiles) and then keeps bouncing... Actually once airborne, `scan` from start=floor(y-0.5) high up finds the ground; the lookahead detects the spike hazard → bounce stays held → on landing it bounces again. So it chain-bounces and eventually lands on a spike.

I need the bot to be smarter: after clearing a hazard, land and roll.

Improvement: only hold bounce if the hazard/wall is within a short distance AND the ball is grounded (i.e., decide at the moment of landing). Since bounce only matters at landing, decide based on the state at landing time. Let me make the bot evaluate the lookahead relative to the ball's current position but only when grounded; when airborne, decide based on where it will land.

Better approach: when airborne, predict the landing point (simulate forward?) — too complex. Simpler: when airborne, hold bounce only if the hazard is within 1.0 tiles ahead (i.e., we're about to land on/near it) — no...

Alternative simpler bot: "hold bounce only when grounded and an obstacle is within 1.5 tiles ahead". When airborne, release bounce. Then the ball lands (settles with restitution) and re-evaluates at the ground. That gives a single hop per obstacle ✓.

But then when it lands short (e.g., in the middle of a spike field) it dies. Let's see: the bot bounces when a spike is within 1.5 tiles ahead. At speed 6, the hop covers ~6.2 tiles → it lands well past the spikes ✓. Then it's grounded, no hazard within 1.5 → rolls ✓.

But careful: the ball's hop from the takeoff point covers 6.2 tiles only at max speed. If the bot triggers the bounce when the hazard is 1.5 tiles ahead, it lands 6.2 tiles later ✓ past the hazard ✓.

Risk: for a 2-tile spike patch, takeoff at hazard-1.5 → lands at hazard+4.7 ✓ safe.

For the step wall: bounce when the wall is within 1.5 → the ball rises 3 tiles and moves right ~? It's blocked by the wall, then accelerates in the air → lands on the step ✓ (as observed earlier).

For the pad: the bot rolls onto the pad (no bounce needed) ✓.

Let me change: `keys.bounce = grounded && (hazard||wall||hole within 2.0)`.

Hmm, but there's a subtlety: at the moment of landing, `b.grounded` is from the previous step. In physicsStep, the landing is detected within the step, using keys.bounce as set before the step. So the bot's decision at the previous step (when airborne, just before landing) matters. If we require grounded to hold bounce, then at the step just before landing the ball is airborne → bounce released → the ball lands without bounce → settles → next step it's grounded → decides → bounces. That adds a 1-step delay but works ✓ (the ball touches the ground for one step, then bounces).

But careful: if it lands ON a spike, it dies before it can bounce. The lookahead must trigger the bounce before landing on the hazard. Since the bot looks ahead 2.0 tiles while airborne, and the hazard is detected → bounce held ✓ (I need the lookahead to work while airborne too).

Let me refine: hold bounce if (hazard within 2.2 ahead measured from the landing surface) OR (wall within 2.2). And when airborne, the landing surface is found by scanning down ✓. But the issue was chain-bouncing: while airborne over the spikes, the lookahead keeps seeing... after clearing the spikes, at x=37 airborne, the lookahead at cols 38-39 sees spikes → bounce held → lands at ~40 which is past the spikes ✓ but bounce held → bounces again at 40. Then it's airborne again, lookahead at cols 41-42... no hazard (43-44 spikes are 3-4 ahead) → hmm, at x=40 airborne, d up to 2.6 → cols 41,42,43 → col 43 is a spike → bounce held → lands at ~46 past the spikes ✓ but bounces again...

So the chain continues because the lookahead range (2.6) is shorter than the hop length (6.2). Fix: when airborne, look further ahead — the lookahead range should scale with the current horizontal speed and remaining airtime. Or: when airborne, only hold bounce if the hazard is within the predicted landing zone.

Simplest robust fix: when airborne, predict the landing x by a cheap forward simulation? We can't easily simulate without cloning state.

Alternative: when airborne, hold bounce only if the hazard is within `d <= 1.0` (i.e., we're about to land right on it) — meaning the landing point is very close to the hazard. Hmm, but the ball lands where it lands; if the hazard is 1 tile ahead while airborne, the landing is imminent.

Actually, let me think about what a competent human does: hop over each spike patch, land, roll, hop again. The bot can do: hold bounce only when grounded and hazard/wall within 2.2 tiles ahead. When airborne, release bounce. Then:
- Grounded at x=36, spikes at 38-39 → within 2.2 → bounce → hop → lands at ~42.2 (6.2 tiles). Hmm, that lands ON the spike at 43? No: 36+6.2 = 42.2 → col 42, which is ground (spikes at 43-44) ✓. Then grounded at 42.2, spikes at 43-44 within 2.2 → bounce again → hop from 42.2 → lands at 48.4 ✓ past. Good.
- But what if the hop lands ON a spike? E.g., grounded at x=37 → hop lands at 43.2 → spike → death. The bot's decision at 37 (grounded): spikes at 38-39 within 2.2 → bounce → hop → lands at 43.2 → spike → death. Hmm! That's a problem: the bot bounces at the wrong spot.

But wait — the hop from a grounded position: the ball takes off and lands 6.2 tiles later only at max speed. The bot holds right always → speed 6 ✓. So the landing is deterministic: current x + ~6.2.

So the bot should choose takeoff points such that the landing is safe. A smarter bot: when grounded, evaluate the landing point x_land = x + hopDist(vx) and check whether the path (from x to x_land) contains a hazard at ground level and whether x_land is safe. If the path has a hazard and x_land is safe → bounce. If x_land is unsafe → don't bounce (roll forward) and re-evaluate next step (rolling, the hazard detection triggers earlier).

Hmm, but if it rolls into a spike it dies. So it needs to bounce at the right time. Let's compute: it should bounce when the hazard is just ahead (within ~1 tile) so the landing is hazard+5.2.

Let me implement a proper lookahead: when grounded, for each candidate action:
- ROLL: the ball continues at vx. Check the ground ahead: if a hazard (spike) or a wall is within, say, 1.0 tiles → rolling is unsafe.
- HOP: landing at x + hopDist. Check that the ground from x+1 to landing is clear of spikes at the surface, and the landing tile is solid and no wall blocks the trajectory... complex.

Simpler heuristic that works well: bounce when the nearest hazard/wall ahead is within [0.6, 1.6] tiles. That way the landing is ~4.6-5.6 tiles past the hazard ✓ safe for 2-3 tile spike patches.

But if the hazard is farther than 1.6, don't bounce (roll closer). If the hazard is closer than 0.6 (too late), too bad.

Let me implement: find the distance to the nearest hazard/wall ahead (dHaz). Then:
- if grounded and dHaz <= 1.7 → bounce.
- if airborne → bounce only if the predicted landing is on/near a hazard. Predict landing: while airborne, estimate the remaining fall time... 

Alternative for airborne: just release bounce when airborne. Then the ball lands with restitution (small bounce) and settles. If it lands on a spike → dead. But we designed the takeoff so the landing is safe ✓.

Hmm, but there's a case: the pad launch (6 tiles) → the ball flies far. When airborne after a pad, releasing bounce is fine ✓.

And the L4 pad → high crumbling bridge: the ball lands on the bridge ✓ (bounce released → it lands and settles, keeps rolling right ✓ good, and it needs to keep moving to avoid collapse ✓).

And the L2 pad → plateau ✓.

And the step climb: grounded at the wall → bounce → blocked → rises → lands on the step ✓. When airborne, bounce released → it lands on the step and settles ✓ then continues.

OK let me implement: bounce = grounded && nearestHazOrWallDist <= 1.7. Plus a special case: if grounded and vx≈0 and blocked → bounce.

Also the hoop-seeking suppression: if a ground-level hoop is ahead within 4 tiles and no hazard within 1.7 → don't bounce. Actually if a hazard is within 1.7 we must bounce regardless.

Hmm, but consider L1: hoop at 21 (ground), spikes at 16-17. The bot bounces at ~15 (hazard dist 1.7 → 16-15=1) → hop lands at 21.2 → collects hoop 21 ✓ nice.

Let me also handle the checkpoint collection: the bot must roll along the ground to collect checkpoints ✓ (it rolls when no hazard).

Let me implement and test.

Another consideration: the bot must not bounce when it needs to drop off a ledge (e.g., running off the step at col 28 → it should just fall). With "bounce only when grounded and hazard within 1.7", at the step edge the lookahead scans down and finds the ground at row 14 → no hazard → no bounce ✓ it just falls ✓ good.

But careful: at the step edge, `scan(xf, start)` where start = floor(11.5-0.5) = 11 → at col 29: y=11..13 empty, y=14 solid → r=14. myRow = scan(b.x=28.5, 11) → col 28: y=11 empty, y=12 solid (step) → myRow=12. Lookahead r=14 > myRow-1=11 → not a wall ✓ good.

Now the "hole" case: r >= L.h → hole. With spikes counted as blocked, a spike pit gives r = the spike row → hazard ✓.

Let me now also handle: when the ball is on the ground and the next tile is a spike at the same surface row: scan at that column from start=13 → y=14 is '^' → r=14, t='^' → hazard ✓ dist = d.

Let me code `nearestHaz` as the minimum d over hazards/walls.

Implementation:

```
let dHaz = 99;
for(let d=0.5; d<=4.0; d+=0.25){
  const xf=b.x+d, tx=Math.floor(xf), r=scan(xf,start);
  if(r>=L.h){ dHaz=Math.min(dHaz,d); break; }
  const t=tileAt(tx,r);
  if(t==='^'){ dHaz=Math.min(dHaz,d); break; }
  if(tileAt(tx,r-1)==='^'){ dHaz=Math.min(dHaz,d); break; }
  if(r<=myRow-1){ dHaz=Math.min(dHaz,d); break; }   // step up / wall
}
```
Break at the first obstacle ✓.

Then: `keys.bounce = b.grounded && dHaz <= 1.7;`

Hmm, but for the wall climb: the wall is at col 25 (x 25..26); the ball at 24.5 → d = 25 - 24.5 = 0.5... floor(b.x+0.5) = floor(25.0) = 25 → r = scan(25, 13) = 13 (solid at row 13) → r <= myRow-1 = 13 → wall at d=0.5 ✓ → bounce ✓.

But the ball rolling at speed 6 covers 0.025 tiles per step, so it will be at dHaz<=1.7 for several steps → bounce held from the moment dHaz <= 1.7 → it takes off ~1.7 tiles before the wall → hop lands 6.2 tiles later → at 24.5-1.7+6.2 = ... let me compute: the ball takes off when b.x ≈ 23.3 (dHaz 1.7 → obstacle at 25 → b.x = 23.3). It hops; but it's blocked by the wall at x=24.5 during the rise... Actually the hop trajectory: it rises 3 tiles from y=13.5 → at x=24.5 (1.2 tiles later, t=0.2) its center is 13.5 - (11.489*0.2 - 11*0.04) = 13.5 - 1.898 = 11.6 → bottom 12.1 → still below the step top (12) → collides with the wall face → pushed to 24.5, vx=0. Then it continues rising to apex 10.5, then accelerates right and lands on the step ✓ (as observed).

Good.

Now, what about the L4 plateau (5 tiles high) reached from the pad? The bot rolls onto the pad → pad launch ✓ no bounce needed. But the bot might bounce before the pad if a wall/hazard is within 1.7. In L4, spikes at 13-14, pad at 16-17. The bot bounces at ~13.3 (dHaz 1.7 from spike col 13... obstacle at x=13 → b.x = 11.3). Hmm: `tx = floor(b.x + 0.5)`; for the spike at col 13 (x 13..14), the obstacle is detected when floor(b.x+d) = 13 → b.x + 0.5 >= 13 → b.x >= 12.5 at d=0.5. With d up to 4.0, detection happens when b.x + d >= 13 → at b.x = 9 with d=4. But we break at the first obstacle found scanning d from 0.5 upward → dHaz = 13 - b.x (approx). So bounce triggers when 13 - b.x <= 1.7 → b.x >= 11.3 ✓.

Takeoff at 11.3, hop 6.2 → lands at 17.5 → that's on the pad (cols 16-17) → pad launch ✓ (the pad launches regardless of bounce) → flies 8.86 tiles → lands at 26.4 → on the plateau (22-28) ✓ 

Hmm, but wait: while airborne from 11.3 to 17.5, does it clear the pad? It lands on the pad → pad launch ✓.

Hmm, but actually the hop from 11.3: does it clear the spikes at 13-14? At x=13.5, t=0.367, rise = 4.22-1.48 = 2.74 → bottom 16.24... wait bottom = y+0.5 where y = 13.5 - 2.74 = 10.76 → bottom 11.26. The spike lethal region for row 14 is y ∈ [14.5,15] → the ball is way above ✓ safe.

Good.

Now, when airborne the bot releases bounce → the ball lands on the pad → pad launch (independent of bounce) ✓.

OK. Let me also consider L2's pad #1 at 22-23 with spikes at 15-16 before it. The bot bounces at ~13.3 → lands at 19.5 → rolls → pad at 22 → launch ✓ → lands on the plateau ✓.

L2's pad #2 at 48-49 with spikes at 41-42: the bot bounces at ~39.3 → lands at 45.5 → rolls to the pad at 48 → launch ✓ → lands at 57.4 ✓.

L4's pad #2 at 51-52 with spikes at 46-47 and 53-55: the bot bounces at ~44.3 → lands at 50.5 → hmm, that's just before the pad (col 50 is ground). Then grounded at 50.5: lookahead → col 51 is a pad (solid, r=14, not hazard, not wall) → col 53 is a spike → dHaz = 53-50.5 = 2.5 > 1.7 → no bounce → rolls onto the pad at 51 → pad launch ✓ → flies 8.86 → lands at 51.5+8.86 = 60.4 → hmm, takeoff at the first pad tile col 51 → center 51.5 → lands at 60.36 → col 60 = the solid block (60-63, top y=9) ✓ 

Wait, does it clear the crumbling bridge at row 9 (cols 56-59)? Earlier analysis: from takeoff at 51.5 speed 6, at x=55.5 rise = 5.95 → bottom 8.05 < 9 ✓ clears the bridge's left face; it descends to bottom=9 at x=57.74 → lands on the bridge ✓ (not at 60). Right — it lands on the bridge first ✓.

Good.

Now the crumbling bridge: the bot lands at 57.74, rolls right at 6 → reaches col 60 at t=0.38 s. The X at col 57 collapses at 0.5 s after first landing ✓ the ball is already at col 60 ✓ safe.

Then cols 60-63 solid, then X at 64-65 → the bot runs across ✓ (contact at col 64 at t≈0.66 after landing at 57.74... the X at 64 collapses 0.5 s after first touch; the ball is at 64.5+3 = 67.5 by then ✓ safe).

Then it drops to the ground at col 66+ ✓ and reaches the exit ✓.

Let me now implement the improved bot and test.

Also for level 3: the bot got stuck at x=63.5 (right wall) with hoop 60 remaining. Hoop 60 is at (60,13) — the bot must have hopped over it. With the new policy it should roll to it ✓.

Let me implement.

Also, the bot needs to handle the raised crumbling bridge in L3 (cols 48-50 at row 12) reached by climbing the step at cols 46-47 ✓.

Let me test.

Big progress: no deaths now. But the bot gets stuck:

L1: stuck at x=44.95, vx=0, grounded, hoop 47 remaining. x=44.95 — the spikes are at 43,44. So the ball landed at 44.95 which is ON the spike tile col 44?? It's grounded at y=13.5 → resting on row 14 at col 44 which is a spike → not solid → it should fall. Hmm, y=13.5 and grounded... Let me check: col 44 row 14 = '^'. The ball at x=44.95 center. It's supported by col 45 (row 14 '#')? dx from 44.95 to [45,46] = 0.05 → w = sqrt(0.25-0.0025)=0.4987 → support at y = 14-0.4987 = 13.5013. So the ball rests at 13.5013 ✓ grounded. And the spike lethal region at col 44: x [44.22, 44.78], y [14.5,15]. Ball center (44.95, 13.5): dx = 44.95-44.78 = 0.17, dy = 14.5-13.5 = 1.0 → dist 1.01 > 0.5 ✓ safe.

So the ball is perched at the right edge of the spike patch, vx=0. Why vx=0? Because the bot is holding right but... it's stuck. dHaz: scan from start=13 at xf = 44.95+0.5 = 45.45 → col 45 → y=14 '#' → r=14; tileAt(45,13)='.' → not wall; not spike. d=0.75 → 45.7 → col 45 → same. ... up to d=4 → col 48 → all ground. So dHaz=99 → no hop. wantRoll: hoop 47 at (47.5,13.5), surfY = myRow-0.5 = 13.5 ✓ dx = 2.55 < 6 → wantRoll=true. mustHop = false → bounce=false ✓. So the bot holds right but vx stays 0?!

vx=0 and holding right with ground acceleration 18 → vx should increase. Unless... the ball is stuck against something. Hmm, x=44.95: is there a solid tile blocking? collideX: tiles overlapping: x-r=44.45 → tx 44..45; y-r=13.0 → ty 13..14. Tile (44,14) = '^' not solid. Tile (45,14) = '#' solid: dy = distance from 13.5 to [14,15] = 0.5 → dy >= R (0.5 >= 0.5) → skip ✓. Tile (45,13) = '.' ✓. So no horizontal collision.

Hmm, so why vx=0? Unless the ball is oscillating. Wait — maybe the ball is at 44.95 and the print is at a moment when vx=0... no, it's constant across 2 seconds.

OH. I bet the issue is `keys.right` — the bot sets keys.right=true always. Unless... `keys.bounce` is being set true by the last rule: `if(b.grounded && Math.abs(b.vx)<0.15 && dHaz<4) keys.bounce=true;` — dHaz=99 → false.

Hmm. Let me look: maybe the ball is stuck in a "sink" between the spike tile (non-solid) and the solid tile at 45: the ball rests at y=13.5013 supported only by tile 45 with w=0.4987. When it accelerates right, x increases → dx decreases → w increases → fine.

Wait, actually maybe the ball is being pushed LEFT by collideX. Let's check tile (45,14): dy = 13.5013 < 14 → dy = 14 - 13.5013 = 0.4987 < R ✓ → h = sqrt(0.25 - 0.2487) = 0.0113 → forbidden x interval [45-0.0113, 46+0.0113] = [44.9887, 46.0113]. Ball x = 44.95 → not in [44.9887, ...] ✓ no collision.

Hmm, but what about tile (44,14)? Not solid.

Let me reconsider: y=13.50 exactly? The print shows y=13.50. If y = 13.5 exactly, then for tile (45,14): dy = 0.5 → skip. So the ball is at exactly 13.5, meaning it's supported by... tile (44,14)? Not solid. Tile (45,14) dy=0.5 → skipped. So nothing supports it → it should fall. Unless it's resting on tile (44,14)... no.

Hmm, y=13.50 could be rounded from 13.5013.

Let me just debug this specific stuck state directly.

Actually — maybe the ball IS moving but very slowly, oscillating: it accelerates right, then collideX pushes it back left to 44.9887... no, that's > 44.95.

Let me print more precisely with more steps.

Actually, hold on: maybe the ball is stuck because it's inside the spike's lethal region? No, it's alive.

Let me debug directly.

L2: stuck at x=16.71, y=13.59, grounded, vx=0. Hoops left 29,32,19,45 → so hoops 5 and 8 collected. x=16.71 — the step is at cols 6-9, spikes at 15-16. So the ball is at col 16 (spike) right edge, perched on col 17 (solid). Same situation as L1!

So the pattern: the bot hops over a 2-spike patch and lands right at the edge of the second spike, perched, and then can't move? Let me investigate why vx=0.

Hypothesis: the ball is perched at x = 16.71 with support from tile 17 only, at y = 13.59 (sunk slightly). collideX: tile (17,14): dy = 14 - 13.59 = 0.41 < 0.5 → h = sqrt(0.25-0.168) = 0.286 → forbidden [17-0.286, 18.286] = [16.714, 18.286]. Ball x = 16.71 → just below lo ✓ no collision. Next step: vx increases → x = 16.71 + tiny → inside [16.714,...] → collision → pushed back to 16.714, vx=0.

So the ball is stuck against the "step" formed by the adjacent solid tile because it has sunk into the notch next to the spike. It's resting in the corner: the spike tile is a hole, and the ball sits in the corner against the solid tile's left face, at a height where the face blocks it.

To escape, it needs to bounce (rise) — then it can move right. The bot doesn't bounce because dHaz=99 (no hazard/wall detected: the wall detection uses `r <= myRow-1`; here myRow = scan(16.71, 13) → col 16: y=13 '.', y=14 '^' → blocked → myRow = 14. Lookahead at col 17: r = 14 → r <= myRow-1 = 13? No → not a wall ✓. So the bot doesn't see the wall because the ball has sunk below the surface level.

Fix: the bot should detect that it's stuck (vx ≈ 0 while holding right) → bounce. My rule required dHaz<4. Let me change to: `if(b.grounded && Math.abs(b.vx)<0.2 && keys.right) keys.bounce = true;` — i.e., if holding right but not moving, hop.

That should free it. Let me also make the bot avoid getting into that corner in the first place, but the escape rule is enough.

Hmm, but careful: this rule could trigger spuriously at the exact moment of a landing (vx could be 0 briefly?). vx is never zeroed by vertical collisions, only by horizontal ones. When rolling, vx > 0. At spawn vx=0 → the bot accelerates → fine, but on the very first step vx < 0.2 → bounce triggers → the ball hops at spawn. Harmless.

Actually it could cause the bot to hop constantly if vx stays < 0.2... no, vx grows quickly.

Let me apply: `if(b.grounded && Math.abs(b.vx) < 0.25) keys.bounce = true;`

L3: stuck at x=63.50 (right wall, level width 64) bouncing (y oscillating 10.5-13.3) with hoops 4 and 60 remaining. Hoop 4 missed (it hopped over it at the start? or died and respawned). Hoop 60 missed. It's at the right wall bouncing. The exit is at col 62 — closed because hoops remain.

Why is hoop 60 missed? The bot ran to the wall. Hoop 60 at (60.5,13.5): the bot should have rolled through it. Unless it was hopping. Let me check: after the raised bridge (cols 48-50 at row 12), the bot drops to the ground at col 51 with center ~13.5 and rolls right; spikes at 57-58 → dHaz triggers a hop at ~55.3 → lands at 61.5 → over hoop 60 at 60.5 → missed!

The wantRoll suppression: `mustHop && !(wantRoll && dHaz>1.0)`. Here wantRoll: hoop 60 at dx = 60.5 - 55.3 = 5.2 < 6 ✓ and |h.y - surfY| = 0 ✓ → wantRoll true, dHaz = 57 - 55.3 = 1.7 > 1.0 → suppression kicks in → no hop → the ball rolls into the spikes → death! But deaths=0... Hmm, so suppression didn't apply. Let me re-read: `keys.bounce = mustHop && !(wantRoll && dHaz>1.0);` → mustHop true, wantRoll true, dHaz 1.7 > 1.0 → !(true) = false → bounce = false → the ball rolls into the spikes → death. But deaths=0. So maybe the hop happened earlier.

Hmm, confusing. Let me instead make the bot smarter about hoops: it should collect a ground hoop only if it can reach it safely. Actually the real issue is the bot's crude policy. Since a human plays this, the bot just needs to be good enough to prove completability.

Better approach: make the bot prioritize collecting hoops by choosing when to hop: when grounded, evaluate the hop landing point x_land = x + hopDist(vx) (hopDist ≈ vx * 2*V_BOUNCE/GRAV). If rolling (not hopping) would hit a hazard within 1.0 tiles → must hop. Among hops, prefer the one whose landing is safe.

Alternatively: let the bot hop only when a hazard is within [1.2, 1.7] — a narrow window — so the landing is predictable. And if the ball is rolling and the hazard is closer than 1.2, it's already too late... 

Let me think about the geometry: spikes 2 tiles wide at cols c, c+1 (x from c to c+2). The ball must hop so that its landing point is beyond c+2 + 0.5. Takeoff at x_t, landing at x_t + D where D = vx * 2*V_B/G ≈ 6 * 1.0445 = 6.27. Also the ball must clear the spikes during flight — it does (3-tile height).

Also the takeoff must be before the ball falls into the spike pit: the ball starts falling when its center passes c - 0.5 + ... Actually support ends when the ball's center x > c + 1 + 0.5? No: the ball is supported by the tile at col c-1 (x [c-1,c]) while dx = distance from center to [c-1,c] < R → center < c + 0.5. So the ball starts to sink when center x > c - 0.5? Let me redo: the ground tile before the spikes is col c-1 spanning [c-1, c]. dx = 0 while center ∈ [c-1, c]; then dx = center - c for center > c. Support height = c... hmm the surface row is 14, tile spans y [14,15). w = sqrt(R² - dx²); support y = 14 - w. At center = c, w = 0.5 → y = 13.5 ✓ full support. At center = c+0.5, w = 0 → y = 14 → the ball has sunk 0.5 → and the spike lethal region starts at 14.5 → the ball's bottom at 14.5 → dead.

So the ball must take off before its center reaches ~c + 0.3.

The bot triggers a hop when dHaz <= 1.7 where dHaz ≈ (c - b.x) roughly (since tx = floor(b.x + d) = c when b.x + d >= c → d = c - b.x). So the hop triggers at b.x = c - 1.7 ✓ well before c + 0.3 ✓ good.

Landing at c - 1.7 + 6.27 = c + 4.57 ✓ safe for a 2-wide patch ✓.

Now the hoop issue: the hop lands past a hoop. To fix, I could make the bot hop as late as possible (dHaz <= 0.6) so the landing is c + 5.67... that's worse. Or hop as early as possible: dHaz <= 2.5 → takeoff at c-2.5 → lands at c+3.77.

Hmm, the hoop position relative to the landing is luck.

Alternative approach for the bot: after landing, if it missed a hoop behind it, it can go back left and collect it. Since hoops are on the ground path, the bot could roll back left (holding left) to collect a missed hoop, then run right again. Let me add: if an uncollected hoop is BEHIND the ball within 8 tiles and at rolling level, and no uncollected hoop/checkpoint is ahead, then turn around (hold left) and go get it. That's a robust recovery.

But rolling left over spikes... it would need to hop over them too — the same logic mirrored. Let me implement the bot symmetrically (lookahead in the direction of travel).

That's a cleaner design: the bot has a target (nearest uncollected hoop/checkpoint/exit) and moves toward it, hopping over hazards.

Let me implement:
- target = nearest uncollected hoop or checkpoint (by |dx|), else the exit.
- dir = sign(target.x - ball.x).
- lookahead in that direction for hazards/walls → hop when close.
- stuck rule → hop.

This should collect everything. Let me implement it.

Also, the bot should avoid hopping over a hoop that is directly in front: if a hoop is at rolling level within the hop trajectory... eh, with the "target" approach, the bot stops (releases right) when close to the target? Let me add: if the target is at rolling level and within 1.0 tiles, release the direction key so it rolls in and collects (it will overlap anyway).

Actually the ball collects the hoop when passing within 0.85 → just rolling through it works ✓. The problem is only hopping over it. With the target approach, the bot hops only when a hazard is within 1.7 ahead. If a hoop is between the ball and the hazard, the hop might fly over the hoop. To avoid: if a hoop/checkpoint target is at rolling level and lies between the ball and the hazard, delay the hop until the ball passes the target — but then it might be too late to clear the hazard.

Hmm. Simplest: choose the hop trigger distance adaptively: we need takeoff x_t such that landing x_t + D is safe (not on a spike, and not into a wall) and the target is between x_t and x_t + D... 

Let me simplify: make the bot hop when a hazard is within 1.7 ahead, but if a target (hoop/cp) at rolling level is between the ball and the hazard, then instead of hopping now, keep rolling until the ball is just before the hazard (dHaz <= 0.55) and hop then → landing at c - 0.55 + 6.27 = c + 5.72. Is that safe? The takeoff at c-0.55 is before the sink point (c+0.3) ✓ but marginal. Hmm, at c-0.55 the ball is still fully supported ✓.

Actually, is the takeoff at c-0.55 safe? The ball's center at c-0.55; the ground tile col c-1 spans [c-1,c] → dx = 0 ✓ full support ✓. Then it launches ✓.

Landing at c+5.72. For L3: spikes at 57-58 (c=57) → takeoff at 56.45, landing at 62.72 → col 62 = the exit door (closed!) → the ball lands on top of the closed door? The door occupies rows 12,13 at col 62 → solid when closed. The ball landing at 62.72 from a hop: its bottom reaches 14 at the landing... but the door's top is at y=12 → the ball would hit the door's side/face earlier. Hmm.

This is getting complicated. Let me step back.

The bot's job is only to prove completability. A simpler, more reliable approach: a small search/planner. But that's a lot of work.

Alternative pragmatic approach: tune the LEVELS so that a simple "hold right, hop when needed" bot clears them, while keeping them good for humans. But that risks over-fitting to the bot.

Better alternative: make the bot smarter in a targeted way — a "hop planner": when grounded, simulate a few candidate takeoff times (0, 1, 2, ... steps of delay) using a lightweight forward simulation of the ball (a copy), and pick the first candidate whose trajectory (a) doesn't hit a spike, (b) lands on solid ground, and (c) passes over/through the nearest target if it's at rolling level. That's a real planner but doable: I can write a forward simulator that reuses the same physics with a cloned state.

Actually — I can just clone the whole game state and call physicsStep! The state is global (ball, run.level, keys). I can save/restore ball and keys, and simulate N steps with a candidate key policy, then restore. Since physicsStep mutates only `ball` (and level object states like crumbles/hoops taken), I need to be careful: physicsStep also calls collect() which mutates hoops/crumbles. For planning I should avoid those side effects.

Let me write a separate lightweight simulator `simStep(state, keys)` that duplicates the physics math but has no side effects (no pickups, no death → but I need spike detection, which is side-effect-free ✓). I can refactor game.js to make physicsStep take a state object and a "pure" flag.

Cleaner refactor: make the physics functions take an explicit ball object and a level, and separate the side effects. Let me restructure:

```
function integrate(b, level, input, opts) // pure: returns landing event
```

Then physicsStep calls integrate(ball, run.level, keys) plus collect/spike/exit checks.

For the planner, I'd need crumble states too (they change). For planning over ~1.5 s, crumble changes matter for the crumbling bridges. I can pass a snapshot of crumble states.

This is getting heavy. Let me consider a simpler planner: a greedy "try candidate delays" using a pure re-implementation of the physics in the test file (duplicating ~40 lines). That's acceptable for a test harness — it doesn't affect the game.

Actually, simpler: I can make game.js's physics pure by design:
- `collideX(b)`, `collideY(b)` already take b.
- `physicsStep(dt)` uses globals. Let me add an optional parameter: `physicsStep(dt, pure)` — when pure, skip collect() and updateCrumble() and don't return 'death'/'exit' but return spike info.

And for planning I need to clone the ball and restore it. Crumble states: for planning I'll just treat crumbling blocks as solid (conservative) — good enough.

Let me do that: add `physicsStep(dt, pure)`.

Then the planner in the bot:
```
function plan(){
  // candidate policies: hold right always; hop now then roll; delay hop by k steps then hop; etc.
}
```

Hmm. Let me simplify the planner to: when grounded, evaluate candidate "hop delays" k = 0..N (roll for k steps, then hop, then hold right and no bounce). Simulate each for up to 1.2 s. Score:
- dies (spike) → invalid.
- lands and continues; check the trajectory passes through the target's collection radius → bonus.
- prefer the candidate that survives and, if a target is ahead at rolling level, that collects it.

Then execute the chosen policy for the first step (either bounce now or not), and re-plan each step (or every few steps).

That's a proper greedy planner. Let me implement it — it's maybe 60 lines in the test.

Actually, even simpler and quite effective: plan with a small set of "actions" repeated over a horizon:
- A: roll (no bounce) for the whole horizon
- B: bounce now, then roll
- C: bounce now, then bounce again on landing (chain)
- D: roll 30 steps then bounce, then roll
- E: roll 60 steps then bounce, then roll
- F: roll 90 steps then bounce
- G: bounce, then bounce on every landing until the horizon (chain) etc.

Evaluate each over ~2.5 s horizon: does it die? does it collect the nearest target? does it advance?

Choose the best: prefer survival, then target collection, then distance advanced.

Then apply only the first action (bounce or not) for one step, and re-plan every ~10 steps.

This should work. Let me implement.

To keep it manageable, I'll define a candidate as a function of step index → bounce boolean, generated from a small parameter set: {delay: 0, 20, 40, 60, 80, 100, 120, Infinity} × {chain: false/true}.

Horizon: 400 steps (1.67 s).

Scoring:
- simulate; if spike hit at step s → survival = s.
- targetCollected → +big.
- distance advanced = final x - initial x (in the direction of the target).

Score = (survival >= horizon ? 1000 : survival) + (targetCollected ? 500 : 0) + distance*2.

Hmm, but "roll forever" (delay=Infinity) would survive on flat ground and collect ground targets ✓. And near a spike it dies early → a delayed hop scores better ✓.

Also need the wall-climb case: rolling forever → blocked by the wall → distance 0 → a hop scores better ✓.

Also the pad case: rolling forever → hits the pad → launched → lands on the plateau ✓ survives ✓ good.

Also the crumbling bridge: rolling forever across it ✓ survives (blocks collapse behind) ✓.

Also the L4 pad → high bridge: rolling forever → pad launch → lands on the bridge → keeps rolling → survives ✓.

Also the exit door closed: rolling forever → blocked by the door → distance 0. Fine.

Also the drop off a ledge: rolling forever → falls to the ground ✓ survives.

Great, "roll forever" is the default and hops are used only when needed. This should work well.

One catch: the planner must consider that hopping might be needed to avoid a spike but the "roll forever" candidate dies at the spike → the planner picks a delayed hop ✓.

Let me implement with the pure physicsStep.

Let me refactor game.js: `function physicsStep(dt, pure)`. In pure mode: skip updateCrumble? Crumble timers affect solidity. For planning, I'll skip crumble updates (treat as static) — acceptable.

Also skip collect() in pure mode, but I need to know if a target was collected → I can compute overlap manually in the planner.

And spikeHit() is pure ✓.

Let me implement:

```js
function physicsStep(dt, pure){
  ... movement, landing ...
  if(!pure){ updateCrumble(dt); collect(); }
  if (spikeHit()) return 'death';
  if (!pure && exitTouched()) return 'exit';
  return null;
}
```

Hmm, but exitTouched with a closed door returns false anyway ✓. In pure mode I should still not trigger exit. Keep as above.

Also in pure mode, `keys` is global — the planner needs to set keys. I'll save/restore keys.

Ball clone: save {x,y,vx,vy,grounded,squash,stretch,alive}.

Let me now write the planner bot.

Let me do it.

Also note: `ball.alive` isn't used by physics ✓.

Let me implement in bot.cjs (test-only), then port the final bot into test.js.

Let me write it.

Oops, the second edit was a no-op (identical). I need to actually add the `pure` handling. Let me edit the body.

Wait — `physicsStep` is called from `update(dt)` as `physicsStep(dt)` ✓ (pure undefined → falsy ✓).

But there's a problem: in pure mode, `collect()` is skipped, so `run.doorOpen` won't update and the door stays solid ✓ fine for planning.

Also `hoopsLeft()` etc. unaffected.

Now write the planner bot.

```js
function makeThink(G){
  const {run,ball,keys,physicsStep,DT,tileAt}=G;
  const HORIZON = 420; // 1.75 s
  const CAND = [];
  for(const delay of [0,15,30,45,60,75,90,105,120,135,150,180,210,1e9])
    for(const chain of [false,true])
      CAND.push({delay,chain});

  function snapshot(){ return {x:ball.x,y:ball.y,vx:ball.vx,vy:ball.vy,g:ball.grounded,sq:ball.squash,st:ball.stretch,al:ball.alive}; }
  function restore(s){ ball.x=s.x; ball.y=s.y; ball.vx=s.vx; ball.vy=s.vy; ball.grounded=s.g; ball.squash=s.sq; ball.stretch=s.st; ball.alive=s.al; }

  function simulate(cand, target){
    const snap=snapshot();
    const k={left:false,right:true,bounce:false};
    let collected=false, survived=HORIZON, startX=ball.x;
    for(let i=0;i<HORIZON;i++){
      k.bounce = (i < cand.delay) ? false : (cand.chain ? true : (i === cand.delay));
      keys.left=k.left; keys.right=k.right; keys.bounce=k.bounce;
      const ev = physicsStep(DT, true);
      if(target && !collected && Math.hypot(ball.x-target.x, ball.y-target.y) < 0.85) collected=true;
      if(ev==='death'){ survived=i; break; }
    }
    restore(snap);
    return { survived, collected, dist: Math.abs(ball.x-startX)*(target? Math.sign(1):1), dx: ball.x-startX };
  }
  ...
}
```

Hmm, `keys` must be restored after planning too. I'll set them at the end.

Target selection: nearest uncollected hoop or checkpoint ahead-or-behind; prefer the nearest by |dx|. If none remain, target = exit.

Direction: sign(target.x - ball.x). If the target is behind, hold left instead of right.

Let me include direction in the candidate: dir = sign(target.x - ball.x).

Scoring: 
- if survived === HORIZON → base 1000 else base = survived (prefer longer survival).
- + 3000 if collected.
- + progress toward target: (target.x - finalX) reduced → score += (startDist - endDist) * 3.

Choose max.

Then apply the chosen candidate's first action: keys.bounce = (0 < delay) ? false : true; and chain irrelevant for step 0 unless delay==0 and chain → bounce true.

Re-plan every step is expensive: 28 candidates × 420 steps = 11760 physics steps per decision. If we re-plan every 15 steps, that's ~784 steps per real step → for a 60 s level (14400 steps) → 11 million physics steps. In Node that's maybe 10-30 s. Acceptable-ish. Let me re-plan every 20 steps and use a horizon of 300 with 16 candidates → 4800 per decision, 720 decisions per level → 3.5M steps per level. Fine.

Let me implement.

Edge: the ball must not be planning while airborne — planning still works (it evaluates from the current airborne state) ✓ good, actually better.

Let me write it.

One concern: candidates with chain=true and delay=0 → bounce on every landing → chain hopping. Useful for climbing steps.

Also add a candidate "bounce every landing but only for the first N landings"? Keep simple.

Let me write and test.

Level 3 cleared in 10.5 s with 0 deaths ✓ — the planner works well.

Level 1: the bot dies repeatedly (36 deaths) around x=36-38. It's chain-hopping and landing on the spikes at 38-39. The planner's scoring may be picking chain candidates poorly. Also it respawns at checkpoint 14 (cpLeft=34 → checkpoint 34 not collected).

Level 2: stuck at x=34.5, vx=0, y oscillating 13.5 → 10.53 — it's bouncing against a wall at x=34.5? The plateau is at cols 26-33 (x up to 34). So the ball is at x=34.5 pressed against the plateau's right face?? No — the ball should drop off the plateau. Hmm, x=34.5 with vx=0 and y oscillating upward: it's bouncing in place against the plateau's right wall (cols 26-33, right edge x=34). The ball is at 34.5, i.e., just right of the plateau, bouncing up and down. Why can't it move right? vx=0 constantly... it's holding right presumably. Hmm, unless the bot chose dir=-1 (target behind).

hoopsLeft=32,45 → target = hoop 32 (x=32.5) which is on the plateau top (row 9). The ball is at x=34.5 on the ground → target is to the LEFT → dir=-1 → it presses left against the plateau wall and bounces. It can't get back onto the plateau (needs a 4-tile climb → pad). Deadlock!

So the bot walked off the plateau, missed hoop 32, and can't return. A human would also be stuck there — that's a real design concern! Once you drop off the plateau in L2, you cannot get back up (4 tiles, needs the pad which is on the other side). If you missed hoop 32, the level becomes unwinnable!

That violates "Every area is escapable" and "hoops sit on the critical path" — the hoops are on the path, so a competent player collects them. But a player who misses one and falls off can't recover → the level becomes unwinnable → they'd have to die to reset? Death respawns at the checkpoint but hoops stay collected... and the missed hoop stays uncollected → unwinnable!

Hmm. That's a real risk. "Collapsing must never make a level unwinnable" is stated for crumbling blocks, but generally the level should be completable. A player who misses a hoop and drops off a ledge must be able to get back.

Fix options:
1. Make the plateau re-enterable: put a pad on the far side too, or make the plateau only 2-3 tiles above the ground on the exit side (a staircase down), so the player can hop back up.
2. Place the second hoop before the drop point so it's naturally collected.
3. Ensure the drop-off point is such that the player must traverse the whole plateau.

Best: make the plateau's right side a step-down so returning is possible, OR add a pad after the plateau that lets you get back up. Simpler: lower the plateau's height on the right end: plateau cols 26-29 at top y=10 (pad route), then cols 30-33 at top y=12 (2 tiles above ground) — a step down. Then a player who falls off at col 34 can bounce back up onto the y=12 part (2 tiles ✓) and walk back along the plateau ✓ escapable.

But then the pad route must clear the 4-tile-high part only at cols 26-29. Let me redo L2's plateau: cols 26-30 rows 10-14 (top y=10), cols 31-33 rows 12-14 (top y=12). Hoops at (28,9) and (32,11).

Hmm, the step down from y=10 to y=12 is a 2-tile drop ✓ and back up ✓.

Also the player on the plateau at y=10 walks right and drops to y=12 at col 31 ✓ then to the ground at col 34 ✓.

And from the ground at col 34, bouncing up onto col 33 (top y=12) ✓ 2 tiles ✓ escapable ✓.

Good. Let me apply the same principle to L4's plateau (cols 22-28, top y=9, 5 tiles above ground): if the player falls off at col 29, can they get back? No (5 tiles, pad is behind at 16-17 — they could walk back left to the pad and re-launch ✓ escapable!). Actually yes: the pad at 16-17 is before the plateau, and the ground between (18-21) is open → the player can walk back left, roll onto the pad, and get launched onto the plateau again ✓ escapable ✓. Good, L4's plateau is fine.

But the bot got stuck at x=21.5 in L4, bouncing against the plateau's left wall with vx=0. hoopsLeft=25,61,33,43,68 → target = hoop 25 (x=25.5, on the plateau at row 8) → dir=+1 → it's pressing right against the plateau wall at 21.5 and bouncing. It should have used the pad at 16-17. Why is it at 21.5? It must have approached from the right or bounced past the pad.

Actually the bot probably hopped over the pad. The planner chose a candidate that lands past the pad, then it's stuck against the plateau wall and can't climb (5 tiles). It should go back left to the pad. The bot's target is hoop 25 (to the right) → it keeps pressing right. A smarter bot would realize it's stuck. Let me add: if the ball is grounded, vx≈0 for a while, and pressing against a wall → look for an alternative (e.g., reverse direction). Hmm.

Simplest fix for the bot: add candidates with dir=-1 too (go left). Then the planner would find that going left onto the pad reaches the target ✓. Let me add direction as a candidate dimension: dir ∈ {toward target, away}. That makes the planner much more capable.

Candidates: 16 delays × 2 chain × 2 dir = 64 → 64*340 = 21760 steps per decision. Re-plan every 14 steps → for a 20 s level (4800 steps) → 343 decisions → 7.4M steps. OK.

Let me also reconsider L1's repeated deaths. Let me look at what happens: the bot chain-hops and lands on the spikes at 38-39. With dir candidates and better scoring it may improve. Also the scoring function has a bug: I used `start0(ball.x)` inside the loop after `simulate` already restored the ball — `Math.abs(tg.x-start0(ball.x)) - Math.abs(tg.x-(ball.x))` = 0 always. Then `sc += (Math.abs(tg.x-(ball.x+r.dx)) < Math.abs(tg.x-ball.x) ? |dx|*4 : -|dx|*4)` ✓ that part is fine. Let me clean it.

Also, the survival score: candidates that die at step 50 get 50; candidates that survive get 1000 ✓ strongly prefer survival ✓.

But chain-hopping candidates that survive but land on spikes... they'd die ✓ penalized.

Hmm, L1 deaths=36 means the bot repeatedly died. Let me look at where: it respawns at 14 (checkpoint 14 active, 34 not collected). It reaches ~38 and dies. The spikes at 38-39. Let me trace more finely.

Actually, maybe the problem is the planner's horizon (340 steps = 1.42 s) is too short to see the consequence of a hop that lands safely but then rolls into a spike later. Let me increase the horizon to 500 steps (2.08 s).

Also, the bot re-plans every 14 steps; with a cached bounce decision, it might hold bounce for 14 steps even if that's bad. Actually `cached` is a single boolean applied for 14 steps — if the ball lands during those 14 steps while bounce is cached true, it hops. Let me re-plan every step instead (expensive but more accurate). Let me try re-planning every 6 steps.

Let me also reconsider: maybe the L1 deaths come from the bot chain-hopping over the checkpoint at 34 and then... hmm, deaths happen at spikes.

Let me improve the bot and re-test. Also let me fix the L2 plateau design (that's a genuine level-design issue worth fixing regardless).

Let me also double check L3's raised bridge: if the player falls into the spike pit at cols 48-50, they die (not stranded) ✓ respawn at 44 ✓. And if the player is on the ground at cols 43-45 and the step at 46-47 blocks them, they can bounce up ✓ escapable ✓.

L4's crumble crossing at 36-39 (X at row 14 over spikes at row 15): if the X collapses while the player is standing there → death ✓. If the player is at col 40 (ground) and wants to go back left, the X at 36-39 might be gone → they'd fall into spikes → they can wait for the blocks to return (3 s) ✓ escapable ✓.

L4's high crumbling bridge at 56-59 (row 9): if the player lands there and the blocks collapse, they die ✓. Can they get back? They're on the solid block at 60-63 (top y=9); going left over the bridge requires the bridge to be present ✓ it returns after 3 s ✓. And from 60-63 they can drop right to the ground at col 66 ✓. Fine.

But: the X at 64-65 (row 9) over spikes at row 14. If those collapse while the player is on the solid block at 60-63 and wants to cross right, they must wait for them to return ✓. And the ground at 66-71 is reachable only via the bridge at 64-65 or by dropping from col 63? Col 63 is the right edge of the solid block (x [60,64)); at center 63.5 the ball is supported; moving right past 64.5 → it falls. Below at col 64-65 row 9 is the X bridge (if present, it lands on it ✓; if gone, it falls to row 14 spikes at cols 64-65 → death). Hmm. So if the bridge is collapsed, the player at col 63 can't proceed right safely, but they can wait ✓ (stand on the solid block at 60-63 and wait 3 s) ✓ escapable ✓.

OK. Now let me fix L2's plateau and improve the bot.

Actually wait, there's another consideration for L2: with the plateau split (26-30 at y=10, 31-33 at y=12), the pad launch must land on the y=10 part (cols 26-30). Earlier: takeoff at 22.5 speed 6 → lands at 29.47 ✓ col 29 ✓ within 26-30 ✓. Takeoff at 23.5 → lands at 30.47 → col 30 ✓ (still in the y=10 part) ✓. Speed 4 → lands at 27.15 ✓. Speed 3 → 25.99 → col 25/26 boundary → lands on the plateau's left edge ✓.

Hmm, what if the ball lands at col 31+ (the y=12 part)? Takeoff at 23.5 speed 6 → 30.47 → col 30 ✓. Max takeoff x on the pad is 23.5 (col 23 center). So landing ≤ 30.5 ✓ good.

Actually the ball could land on the pad at col 23 (center 23.5) — yes max. ✓

And the y=12 part at cols 31-33: could the ball land there directly from the pad? It would need to be above y=12 at x=31 → from the pad it's above y=12 (rise > 2) between... h=2 at t = [16.248 ± sqrt(264-88)]/22 = [16.248±13.266]/22 → t1=0.1355, t2=1.344. At speed 6, x(t2) = 23.5+8.06 = 31.56 → but it would have landed on the y=10 part at 30.47 first ✓.

OK.

Now hoops on the plateau: (28,9) on the y=10 part ✓ and (32,11) on the y=12 part ✓.

Let me update gen.js for L2 and regenerate.

Also, let me reconsider L1's difficulty: the bot dies a lot there. Let me check whether the level is actually hard or the bot is dumb. Spikes at 16-17, 38-39, 43-44. Between 38-39 and 43-44 there are only 3 clear tiles (40,41,42). A player hopping over 38-39 at full speed lands ~6.2 tiles later → at 44ish → ON the spike at 43/44! That's the problem: the landing zone between two spike patches is only 3 tiles wide, and a full-speed hop covers 6.2 tiles. So a player at full speed who hops over the first patch lands in the second patch!

That's a genuine design flaw — "Leave room... several clear tiles between spikes and after every landing". I need ≥ 7 clear tiles between spike patches if the player is at full speed, or the player must control speed. Hmm, 6.2 tiles of hop distance at max speed. To be safe, gaps between spike patches should be ≥ 7 tiles, OR the patches should be crossable by rolling (no, they're lethal).

Hmm, but a player can also hop *just* over a patch: takeoff right before the patch and land 6.2 tiles later. If the patch is 2 wide, the landing is 4.2 tiles past the patch's end. So the clear zone after a patch must be ≥ ~4.5 tiles to accommodate a max-speed hop landing, and then the player must be able to stop or hop again.

Actually the player can also brake (friction) after landing: landing at 44.5 in a clear zone... Let me just space the spike patches ≥ 8 tiles apart in L1 and ≥ 6-7 tiles in later levels. Let me recheck all levels:

L1: patches at 16-17, 38-39, 43-44 → gap between 39 and 43 is 3 tiles (40,41,42) ✗. Fix: move the third patch to 47-48 and the exit to 51? Let me redesign L1's tail: spikes at 38-39, then clear 40-49 (10 tiles), hoop at 45, exit at 49. And remove the third patch or place it at 47-48 with the exit further right.

Let me redo L1: W=56.
- ground 0-55.
- spikes 16-17, 38-39, 47-48.
- gap 17→38 = 20 ✓; 39→47 = 7 tiles (40..46) ✓ hmm 7 tiles: a max-speed hop from 36.3 lands at 42.5 ✓ clear ✓ then the player must hop again from ~45 (spike at 47 → takeoff at 45.3) → lands at 51.5 ✓ clear ✓. Good.
- exit at col 53.
- hoops: 6, 11, 21, 27(step top), 34, 44. Hmm hoop 44 is 3 tiles before the spike at 47 — the player hopping over 47-48 takes off at ~45.3, so hoop 44 is collected while rolling ✓.
- checkpoints: 14, 41. Checkpoint 41 banks progress before the 47-48 patch ✓. But the hardest stretch in L1 is the 38-39 and 47-48 patches; checkpoint 41 is between them ✓.
- step at 25-28, shelf at 31-34, crystal at (32,9) ✓.
- hoop at 34? Let me place hoops: 6, 11, 21, 27, 34, 44. Hmm hoop 34 is under the shelf (cols 31-34 rows 10,11) ✓ ground ✓.

Wait, I need to double check the spacing between the step (25-28) and the spikes at 38-39: plenty ✓.

And between the spikes at 16-17 and the step at 25-28: 7 clear tiles (18-24) ✓. A max-speed hop from 14.3 lands at 20.5 ✓ clear ✓ then rolls to the step ✓.

Good.

Now L2: patches at 15-16, 41-42, 50-54. Gap 16→41 huge ✓. 42→50: clear 43-49 = 7 tiles ✓. A hop over 41-42 takes off at ~39.3 and lands at 45.5 ✓ clear ✓. Then the player rolls to the pad at 48 ✓. Good.

But careful: the player must not accidentally hop and land in the 50-54 field. They roll onto the pad at 48 → pad launch ✓ lands at 57.4 ✓.

L3: patches at 25-26, 41-42, 57-58, plus spike pits at 30-33 (under X), 48-50 (under X). Gaps: 26→30: clear 27-29 = 3 tiles ✗! A hop over 25-26 takes off at ~23.3 and lands at ~29.5 → col 29 ✓ clear (27,28,29 are ground with X starting at 30). Then the player is at 29.5 and the X bridge starts at col 30 → they roll onto it ✓ (X is solid) ✓ fine. But if they hop again they'd land at 35.7 ✓ on the ground past the bridge ✓.

Hmm, but the landing at 29.5 is 0.5 tiles from the X bridge start — fine, X is solid and safe.

Actually wait: is the landing at 29.5 safe? The spike pit is at cols 30-33 row 15, and the X at row 14. The ball at center 29.5 is supported by col 29 (row 14 solid) ✓ and col 30 (X at row 14, solid) ✓ safe ✓.

But the checkpoint at 28 is right there ✓ good.

Gap 33→41: clear 34-40 = 7 ✓. A hop from the bridge... the player runs across the X bridge at cols 30-33 and continues to 34+ ✓.

Gap 42→46 (step at 46-47): clear 43-45 = 3 tiles. A hop over 41-42 takes off at ~39.3 → lands at 45.5 ✓ just before the step at col 46 ✓ safe ✓ (the step's wall is at x=46; the ball lands at 45.5 and then must climb ✓).

Hmm, landing at 45.5 with speed 6 → it continues right and hits the wall at 45.5 → stops → climbs ✓ fine.

Gap 50→57: clear 51-56 = 6 tiles. The player drops off the raised bridge at col 51 (falls 2 tiles) at speed 6 → lands at ~51+3.6 = 54.6 ✓ clear ✓ then must hop over 57-58: takeoff at ~55.3 → lands at 61.5 ✓ clear (59-63) ✓ good.

L4: patches at 13-14, 46-47, 53-55, 64-65 (under X), 36-39 (under X). 
- 14→16 pad: clear 15 = 1 tile! A hop over 13-14 takes off at ~11.3 and lands at ~17.5 → on the pad (16-17) → pad launch ✓ fine. Or the player rolls into the pad? They'd hit the spikes. They must hop. Landing on the pad is fine ✓.

Hmm, but what if the hop lands at 17.5 (col 17, the second pad tile) → pad launch from 17.5 → flies 8.86 → lands at 26.4 ✓ on the plateau ✓ good.

- 39 (X pit) → 46: clear 40-45 = 6 ✓.
- 47 → 51 (pad): clear 48-50 = 3 tiles. A hop over 46-47 takes off at ~44.3 → lands at 50.5 ✓ clear ✓ then rolls onto the pad at 51 ✓.
- 55 (spike field) → 56 (bridge): handled by the pad ✓.
- 65 → 66: the player runs off the bridge ✓.

OK. Also L4's spike field 53-55 is crossed by the pad ✓.

Now, one more spacing check for L1: after the hop over 47-48 landing at 51.5, the exit at 53 ✓.

Let me also reconsider: is a 2-tile spike patch always lethal when rolling into it at max speed? Earlier analysis: crossing 2 spike tiles at speed 6 → the ball falls ~1.22 tiles → dies ✓. And at low speed it definitely dies ✓.

Hmm, but what about a 1-tile gap? Not used.

Now let me also double check the "leave room" requirement: "Space hazards generously — several clear tiles between spikes and after every landing". With ≥7 clear tiles between patches ✓.

Let me now regenerate the levels with the L1 and L2 fixes, then improve the bot.

New L1 (W=56):
- bedrock row 15, surface row 14 '#'
- spikes: 16-17, 38-39, 47-48
- step: cols 25-28 rows 12,13
- shelf: cols 31-34 rows 10,11
- crystal (32,9)
- spawn (2,13)
- hoops: (6,13),(11,13),(21,13),(27,11),(34,13),(44,13)
- checkpoints: (14,13),(41,13)
- exit: (53,13),(53,12)

Check hoop 34 under the shelf (cols 31-34 rows 10,11) ✓ ground row 14 at col 34 ✓.

Check the crystal route from the step (right edge x=29) to the shelf (cols 31-34) ✓ verified earlier.

New L2 (W=64): plateau split: cols 26-30 rows 10-14, cols 31-33 rows 12-14. Hoops (28,9) and (32,11).

Everything else the same.

Let me update gen.js and regenerate.

Then improve the bot with direction candidates and a longer horizon.

Let me do it.

L2 plateau now: cols 26-30 rows 10-14 and cols 31-33 rows 12-14. Row 11 shows `........O...######........#####.O...` → cols 26-30 '#####' ✓ and col 32 'O' (hoop at row 11 on the y=12 step) ✓. Row 10: cols 26-30 '#####' ✓. Row 12: `......####................########..........................D...` → cols 26-33 '########' ✓ (both parts solid at row 12) ✓.

Hoop at (28,9) ✓ on the y=10 part. Hoop at (32,11) ✓ on the y=12 part (surface y=12 → ball occupies row 11 ✓).

Now update game.js's LEVELS maps with the new L1 and L2.

Then improve the bot.

Let me update game.js maps.

Now improve the bot: add direction candidates (toward / away from target), longer horizon, and re-plan more often.

Let me rewrite bot.cjs.

Candidates: dir ∈ {+1 (toward target), -1 (away)}, delay ∈ {0,12,...,230,∞}, chain ∈ {false,true}. That's 2*16*2 = 64 candidates × 400 steps = 25600 physics steps per decision. Re-plan every 10 steps → for a 15 s level = 3600 steps → 360 decisions → 9.2M steps. Each physics step is maybe 1-2 µs → ~15 s per level. Acceptable but slow. Let me reduce: delay set of 10 values, chain 2, dir 2 → 40 candidates × 400 = 16000 per decision.

Let me also prune: if the ball is far from any obstacle, "roll toward target forever" is obviously good — but let's keep it simple and just run it.

Let me test.

Also, the scoring should prefer candidates that end in a "safe, non-stuck" state: if the final vx ≈ 0 and it's pressed against a wall, penalize.

Let me add: if survived full horizon and final |vx| < 0.3 and the candidate held a direction → penalty -200 (stuck).

Let me write it.

Level 4 completed by the bot ✓ (19.9 s, 0 deaths).

Levels 1-3: the bot is stuck at the spawn area (x=5.5 or 24.5) with vx=0. It's jammed against the step wall (cols 6-9 at L2/L3, x=5.5) and can't climb.

Why? The "jammed" penalty -900 applies, but maybe all candidates are jammed. The step climb requires: hold right + bounce (chain). Candidate dir=1, delay=0, chain=true → the ball bounces on every landing and should climb. Let me check why it fails.

Earlier (dbg2) I verified the climb works when starting at the step edge with bounce held. Let me test the candidate directly.

Hmm — the issue might be the "collected" bonus dominating: the target is hoop 8 (on the step top at (8.5,11.5)) — the chain candidate should collect it.

Wait, in L2 the bot is stuck at x=5.5 which is exactly the wall face (step at cols 6-9 → left face at x=6 → the ball is pushed to 5.5) ✓. vx=0. So it's pressing right and being blocked.

If bounce were held, it would rise. So the chosen candidate has bounce=false. Why? Maybe the chain candidate dies or scores worse.

Hmm, `keys.bounce = best.delay===0` — for chain candidates with delay=0, bounce=true ✓.

Let me debug: print the chosen candidate and the scores at the stuck state.

Possible bug: in `simulate`, for candidates with dir=-1, the ball moves left away from the wall → survives the full horizon, vxEnd = -6 (not jammed), and d1 (distance to target) increases → score = 2000 + (d0-d1)*6. d0 = |8.5-5.5| = 3; after moving left for 420 steps at 6 t/s → 10.5 tiles → x = -5 → clamped by the world wall at x=0.5 → d1 = 8 → score = 2000 + (3-8)*6 = 1970.

For dir=+1 chain delay=0: the ball climbs the step and collects hoop 8 → +6000 → score ~8000. That should win... unless it dies or fails to collect.

Unless the chain candidate doesn't actually collect the hoop. Let me test the climb from x=5.5.

Hmm, wait: at x=5.5 the ball is at the wall. With bounce held, it rises 3 tiles → apex center 10.5 → the step top is y=12 → the ball must reach center 11.5 to land on it ✓. Then it accelerates right in the air ✓ lands on the step ✓ collects hoop 8 at (8.5,11.5)? The ball on the step top has center y=11.5 ✓ and passes x=8.5 ✓ collected ✓.

So why isn't it chosen? Let me actually debug by printing the top candidates.

Oh! I see a bug: `physicsStep(DT, true)` — in pure mode it skips `updateCrumble` and `collect`, fine. But `spikeHit()` returns 'death' ✓. And `exitTouched` skipped ✓.

Another bug: `targets()` returns objects from `run.level.hoops` — and `simulate` uses `tg` — fine.

Hmm, but `think()` is called every step, and `physicsStep(DT,true)` mutates `ball` during simulation, then `put(s)` restores. But `keys` are left at the last simulated candidate's values — then we set them at the end ✓.

Wait, there's a subtle issue: `run.doorOpen` — not affected.

Let me print diagnostics.

Actually — maybe the problem is that the ball at x=5.5 is NOT grounded? It shows y=13.50, vx=0.00. Should be grounded.

Let me debug directly.

Interesting! The climb works in the "live" run: the ball rises to y=8.5 and travels right — but it flies OVER the step (the step top is y=12, and the ball is at y≈8.5-11.4, above it) and lands... at x=11.07 y=8.80 — it's still airborne. It's chain-hopping and overshooting the step, landing past it (the step is cols 6-9, x up to 10).

Hmm, at x=8.07 y=9.80: the ball's bottom is 10.3, above the step top (12) → it's flying over the step without landing on it. Because it chain-hopped from the ground with a full 3-tile bounce, it goes above the step and lands on TOP of it only when descending to bottom=12. Let's see: at x=11.07 y=8.80 → it's descending? vy? It bounced again at some point.

Actually the chain policy bounces on EVERY landing, so when it descends onto the step top it bounces immediately and doesn't "collect"... but collection happens on overlap regardless ✓. Hoop 8 at (8.5, 11.5): the ball at x=8.07 y=9.80 → distance = sqrt(0.43² + 1.7²) = 1.75 > 0.85 → not collected. At x=7.15 y=11.36 → distance = sqrt(1.35²+0.14²)=1.36 → not collected. Hmm, the ball passes above the hoop.

The ball's bottom at x=7.15 is 11.86, and the step top is 12 → it hasn't landed yet. It continues right and its bottom reaches 12 at x≈7.5 → lands on the step at center 11.5 → at that moment x≈7.5, hoop at 8.5 → distance 1.0 > 0.85 → misses! Then it bounces immediately (chain) and flies off.

So chain-hopping over/onto a 2-tile step lands it near the left edge and it bounces away before reaching the hoop at col 8.

A human would land and roll. The bot needs a candidate that hops once and then rolls: dir=1, delay=0, chain=false → final x=11.66, y=13.50 → it landed past the step? y=13.50 means it's on the ground, not on the step. Hmm, x=11.66 y=13.5 → past the step (cols 6-9) on the ground. So it hopped over the step entirely and landed on the ground beyond it → missed hoop 8.

Hmm! So with a single 3-tile bounce from the wall, the ball flies over the 4-tile-wide step and lands past it. Because the step is 4 tiles wide (cols 6-9 = x 6..10) and the hop covers ~6 tiles... but the ball is blocked by the wall initially, so it starts with vx=0 and accelerates. Let me re-look: dir=1 delay=0 chain=false → final x=11.66 y=13.5. So it cleared the step and landed at 11.66 on the ground.

So the hoop at (8.5,11.5) on the step top is missed. A human would bounce and land ON the step (they'd modulate: bounce when closer to the wall, or not hold right during the rise).

Hmm. This is a bot competence issue, not necessarily a level issue. A human can land on the step top easily.

But it does reveal: the step is 4 tiles wide and a full-speed bounce from the wall flies over it. Is that a problem for a human? No — a human can control it (e.g., bounce while adjacent to the wall and hold right only after clearing the height, or approach slower).

But for the bot, let me add more candidate variety: e.g., "hold right for k steps then stop holding right for m steps then hop" — too many combos.

Alternative: add candidates where the direction is released for a while: dir=1 with a "coast" phase. Let me add a candidate family: {dir, delay, chain, brake} where brake means: after the hop lands, release the direction key for 30 steps (so it stops on the ledge). Hmm.

Simpler: add candidates with dir=1 but with a "slow approach": hold right for `delay` steps then release direction (coast/brake) for the rest, with bounce at delay. Hmm.

Let me think about what the bot needs to do at the step: approach slowly (brake), then hop → it lands on the step top and rolls.

Let me add a candidate family: `brake` = for steps [delay, delay+60) hold no direction; then hold dir again. Combined with bounce at delay.

Actually, a cleaner approach: add candidates parameterized as a small program:
- phase A: hold dir for `a` steps (a ∈ {0, 10, 20, 30, 1e9})
- bounce at step `b` (b ∈ {0, 10, 20, ..., 1e9 meaning never}) — hmm.

Let me simplify differently: give the bot an explicit "stuck recovery" behavior. When the ball is grounded, pressing a direction, and vx ≈ 0 for > 0.3 s (jammed against a wall), then: hold bounce and release the direction for 0.25 s (so it rises straight up), then press the direction. That's exactly what a human does to climb a wall: bounce while against it, then move.

Actually the issue is it overshoots horizontally. Let me instead implement: when jammed, bounce and hold the direction only while above the obstacle height... complex.

Alternative pragmatic approach: accept that the bot may not perfectly collect every hoop, and instead verify completability with a *scripted* per-level input sequence (a "solution replay") that I design. That's more work but deterministic and also serves as documentation of the intended route.

Hmm. Middle ground: improve the bot with a "brake" candidate family and see.

Let me add candidates: {dir, mode} where mode ∈:
- 'roll': never bounce
- 'hopNow': bounce at step 0, then never chain
- 'hopChain': bounce always
- 'hopThenBrake': bounce at 0, then release direction for 40 steps after the first landing... hard to detect landing in the candidate spec.

Simpler: 'brakeRoll' = release direction entirely for the horizon (ball decelerates) + bounce chain. Hmm.

Let me parameterize with a "hold" pattern: holdDir = (i >= holdFrom) i.e., start holding the direction after `holdFrom` steps, combined with bounce pattern (never / at 0 / chain). And also a "stop" pattern: hold only for the first `k` steps.

Let me define candidates as: dir ∈ {1,-1}, bounceAt ∈ {never, 0, chain}, dirPattern ∈ {always, from0toK(k=25), afterK(k=25), alternating(30)}. That's 2*3*4 = 24 candidates. Plus delays for the hop: hopDelay ∈ {0, 20, 40, 60, 80, 120, never} → 2*7*3(bounce style: single/chain)... getting big.

Let me try a different, more powerful approach: a short-horizon beam search over the two binary inputs with a scoring function, using a beam of states. Beam search: at each step, branch on bounce ∈ {0,1} and dir ∈ {-1,0,1}; keep the top N states by a heuristic. Horizon 300 steps, beam 40 → 300*40*3 = 36000 sims per decision — too slow per step, but we can plan every ~30 steps.

Hmm, cost: 36000 physics steps per plan; plan every 30 steps → 1200 physics steps per real step → for a 20 s level (4800 steps) → 5.8M ✓ fine.

Heuristic for beam states: prefer states that (a) haven't died, (b) are close to the target, (c) not jammed. But a greedy heuristic may fail for jumps that temporarily move away.

Honestly, maybe the simplest robust approach: write scripted solutions per level (a list of timed inputs) — but tuning them by hand is tedious.

Alternative: improve the bot's climb behavior specifically. The core problem is landing on a ledge. Let me add a candidate family "hop and brake": bounce at delay, and for steps >= delay, hold dir for the first 20 steps then release for 45 steps, then hold again. This makes the ball rise mostly vertically, land on the ledge, stop, then proceed.

Let me just add a few "brake" patterns and test. Patterns (relative to delay):
- P0: hold dir always
- P1: hold dir for [delay, delay+20), release for [delay+20, delay+70), hold after
- P2: release dir for [0, delay) (approach slowly), hold after delay
- P3: hold dir for [0,delay+15), release [delay+15, delay+55), hold after

Let me implement pattern as a function of i and c.

Let me code:
```
function dirAt(c,i){
  if(i < c.delay) return c.pre;         // pre-delay direction (1, -1, or 0)
  const j = i - c.delay;
  if(c.post === 'always') return c.dir;
  if(c.post === 'brake') return (j<20)? c.dir : (j<70 ? 0 : c.dir);
  if(c.post === 'slow') return (j<50)? 0 : c.dir;
}
```
with c.pre ∈ {dir, 0}.

Candidates: dir ∈ {1,-1}, delay ∈ {0,15,30,45,60,80,110,150,1e9}, post ∈ {always, brake, slow}, chain ∈ {false,true}, pre ∈ {dir, 0}. That's 2*9*3*2*2 = 216 candidates × 420 steps = 90k per decision — too slow if done every step.

Let me reduce: dir ∈ {1,-1}, delay ∈ {0,20,45,80,130,1e9}, post ∈ {always,brake,slow}, chain ∈ {false,true} (pre = dir always, except post='slow' implies pre=dir). → 2*6*3*2 = 72 candidates × 420 = 30k per decision. Plan every 20 steps → 1500 per real step → 20 s level = 4800 steps → 7.2M ✓ OK.

Let me implement and test.

Actually, let me reconsider the whole approach. Time is finite. An alternative validation: verify completability by construction with a "guided" bot that has explicit knowledge: e.g., for each level, a hand-written waypoint script: a list of (targetX, action) instructions. Hmm.

Let me just try the improved candidate set; if the bot clears all 4, great.

Let me implement.

Worse — the added candidates confused the scoring (the "slow"/"brake" candidates score well because they don't move but aren't penalized enough, or the jam penalty isn't applied).

Level 4 got worse (stuck at spawn).

The scoring is the problem: candidates that don't move get d0-d1 = 0 and vxEnd=0 → -1200 → score 800. Candidates that move toward the target get +6*dx. Hmm, for L4 at spawn: hoop 5 at x=5.5, d0=3. A candidate that moves right 3 tiles collects it → +6000 ✓ should win. Unless it dies... no spikes near spawn.

Hmm, L4 stuck at x=2.50 with y oscillating 11.59→13.04 → it's bouncing in place at spawn. So the chosen candidate has chain bounce and dir... vx=0.

I think the issue is that `keys.bounce = best.delay===0` only applies the first step of the candidate, but the candidate's benefit may depend on its later phases. With re-planning every step, a candidate that says "bounce now, then brake" gets only "bounce now" applied. That's fine.

But a candidate that bounces now and then brakes scores: it hops in place, lands, doesn't move → dx≈0, vxEnd≈0 → -1200 → 800. A candidate that rolls right collects hoop 5 → 2000 + 6000 + ... → should win.

Unless... `collected` is computed with `tg` = hoop 5 at (5.5,13.5) ✓ and rolling right from 2.5 → collects at x≈4.65 ✓ +6000.

So why isn't it chosen? Unless the roll candidate dies. At spawn x=2.5, rolling right: spikes at 13-14. Horizon 420 steps = 1.75 s → at 6 t/s it travels 10.5 tiles → reaches x=13 → spike → death at ~step 250 → survived=250 → score 250 + 6000 (collected hoop 5) + progress... = ~6300.

A candidate that hops over the spikes and survives: 2000 + maybe collects hoop 5 while hopping? Hoop 5 at (5.5,13.5): a hop from 2.5 → the ball is airborne, its bottom rises → at x=5.5 the ball's center is ~11 → distance 2.5 → not collected. Score 2000 + progress (d0 - d1) where d1 = |5.5 - (2.5+10.5)| = 7.5 → (3-7.5)*6 = -27 → 1973.

So the roll candidate (6300) beats the hop candidate (1973) → the bot rolls into the spikes... but deaths=0 for L4. Hmm, because after dying it respawns... deaths=0 though.

Wait, L4 shows x=2.50 bouncing at spawn. So it never even rolled. Confusing.

Hmm, maybe the issue is `keys` state leaking: `simulate` sets keys, and after the loop the last candidate's keys remain; then we set keys for the chosen candidate ✓. But `think()` is called only when run.state==='play' in dbg.cjs ✓.

Hold on — maybe the problem is that `physicsStep(DT, true)` in pure mode still calls `collect()`? No, I guarded it. Let me verify the edit applied correctly. Let me grep.

Also `updateCrumble` skipped ✓.

Hmm, but there's another side effect: `spikeHit()` is fine.

Let me check: does `physicsStep` in pure mode still modify `run.respawn`? No.

Let me debug L4 at spawn: print the top 5 candidates with scores.

Actually — I wonder if the bug is that `run.level.checks.filter(c=>!c.taken)` and hoops are re-sorted every call, and `tg` might be a checkpoint far away, making rolling right score poorly. At L4 spawn: hoops 5 (x=5.5), 25, 33, 43, 61, 68; checkpoints 30, 49. Nearest = hoop 5 at 5.5 ✓ d0=3.

Let me just print diagnostics.

Actually, wait. I bet the real problem is different: `keys.bounce = best.delay===0` — for candidates with delay=1e9 (never bounce), delay===0 is false → bounce false ✓. For delay=0 → true.

Hmm, at L4 spawn the ball is bouncing in place → bounce is being held → the chosen candidate has delay=0. Which candidate with delay=0 scored highest? Possibly a 'brake' or 'slow' one: bounce at 0, dir for 18 steps, then release 47 steps... it hops in place mostly, dx small, vxEnd 0 → -1200 → 800. That shouldn't beat 6300.

Unless the roll candidate's `collected` isn't detected. `Math.hypot(ball.x-tg.x, ball.y-tg.y)<0.85` — the real game uses 0.85 for hoops ✓ same.

Hmm, but in the real game `collect()` is called inside physicsStep (non-pure) ✓.

Let me just print the top candidates for L4 at spawn.

Let me do that quickly.

The planner picks dir=1, delay=0, post='slow', chain=false → bounce=true at step 0. So the ball bounces at spawn, then dir=1 for 18 steps, then released for 55 steps... but re-planning every step means the plan is re-evaluated each step, and the "slow" pattern never actually gets its later phases.

The problem: re-planning every step with a candidate whose benefit comes from a multi-step pattern → we only apply step 0. And step 0 for 'slow' candidates is dir=1, bounce=true. So the ball bounces at spawn every time it's grounded → chain hopping in place → stuck.

Fix: apply the candidate's pattern for several steps before re-planning (commit to a plan for N steps). Let me commit for e.g. 25 steps, then re-plan. That way 'slow'/'brake' patterns actually execute.

But committing can be brittle. Let me commit for 20 steps and re-plan.

Also, prefer candidates with post='always' slightly (they're simpler and more predictable)? No — the brake patterns are needed for ledge landings.

Let me implement commit: store the chosen candidate and apply dirAt(c, k) for k = 0..commit-1.

Let me test with commit=20.

Also, the tie between chain true/false: identical scores; whichever comes first wins.

Let me test.

Still stuck. L4 stuck at spawn bouncing in place with vx=0 — but the planner said dir=1. vx=0 while holding right at spawn? That means the ball is being blocked horizontally at x=2.5. What's at x=2.5? Spawn is col 2, ground everywhere. Nothing blocks.

Unless... keys.right is false! `dirAt(plan, pk)` with post='slow' and delay=0: for j<55 → return 0 → no direction! So for the first 55 steps the ball has no direction input. And bounce at i===delay=0 → bounce only at step 0.

So the ball bounces once at step 0, then coasts with no input for 55 steps. Then dir=1 for the remaining... but COMMIT=22 means we only execute 22 steps of the plan, all with dir=0 → the ball just bounces once and then sits. Then re-plan → same choice → infinite loop.

The 'slow' candidates score highest because they survive and collect the target... wait, they collected the target in simulation because after 55 steps of coasting they then drive right and collect ✓. But committing only 22 steps means we never get past the coast phase.

Fix: prefer 'always' candidates, or make COMMIT larger (e.g., 60), or score candidates by their behavior in the first COMMIT steps too.

Better fix: score candidates primarily on their first COMMIT steps (immediate behavior) plus the long-horizon outcome. Or simply drop 'slow' and keep 'brake' (which drives for 18 steps first, then coasts).

Hmm, but the earlier problem (L2/L3 step climb) needs a brake-like behavior.

Let me reconsider the step-climb problem: the ball at the wall (x=5.5) needs to get onto the step top (y=12, cols 6-9). Options: bounce while pressed against the wall, then move right in the air → it lands on the step near col 7.5 and (with chain) bounces again. With 'brake' (drive 18 steps then release 47), the ball: bounces at step 0, drives right 18 steps (0.075 s) → barely moves; it's blocked by the wall anyway. Then releases for 47 steps → it rises and falls back onto the ground at ~5.5 → lands → then drives right again... it lands before the release ends. Hmm.

Let me think about what actually works for the climb:
- The ball is at the wall. Bounce (3 tiles). It's blocked horizontally until its bottom clears y=12 (center 11.5), which happens at rise 2 → t=0.221 s. Then it needs to travel right ≥ ~1 tile to land on the step. With air accel 7.2 from vx=0, in the remaining window (until its bottom returns to 12 at t=0.824) it travels 1.31 tiles → lands at 6.8 ✓ on the step ✓.

So the required input: hold bounce at the takeoff, hold right continuously. That's candidate dir=1, delay=0, chain=false, post='always'. Let's check: at step 0 bounce=true, then bounce=false for the rest. The ball takes off with vy=-11.489 ✓ (bounce held at the landing that step). Then it rises; at t=0.221 it can move right; it holds right ✓; it lands on the step at t=0.824 at x≈6.8 ✓. Then bounce=false → it settles on the step ✓ and rolls right → collects hoop 8 at 8.5 ✓.

That candidate should score: survives ✓, collects ✓ (+6000), dx ≈ ... it continues right and eventually hits the spikes at 15-16 in L2 → dies at some step. Horizon 420 steps = 1.75 s. From x=5.5: climb (0.824 s) → lands at 6.8 → rolls right, collects hoop 8 → continues to the spikes at 15-16 → at 6 t/s from 6.8, in 0.926 s remaining it travels 5.6 → x=12.4 → doesn't reach the spikes ✓ survives.

So it should score 2000+6000+progress. Progress: d0 = |8.5-5.5| = 3; final x=12.4 → d1 = 3.9 → (3-3.9)*6 = -5.4 → total ≈ 7994.

And the 'slow' candidates score 7996 (slightly higher). So 'slow' wins but is broken under commit.

Fix: remove 'slow' (or make its coast phase shorter than COMMIT). Let me set post options: 'always' and 'brake' (drive 18, coast 47, drive). With COMMIT=22, 'brake' executes the drive phase ✓.

But is 'brake' ever better than 'always'? For the ledge landing case (L1's step at cols 25-28 where a full-speed hop flies over), 'brake' would: drive 18 steps then coast → the ball decelerates... Actually coasting in the air doesn't decelerate (no air friction). Coasting on the ground decelerates at 12 t/s².

Hmm. Let me think about the L1 step problem: the ball at x=24.5 (wall), speed 6. It needs to land on the step top (cols 25-28, x 25..29). A hop from 24.5: blocked until rise 2 (t=0.221), then travels 1.31 → lands at 25.8 ✓ on the step ✓. Wait, that's the same as L2 — it works! Earlier the failure was because the ball arrived at the wall at full speed and bounced... let me recheck: with chain=false, the ball bounces once at the wall and lands on the step at 25.8 ✓.

Earlier in L1 the bot got stuck at x=24.5 with vx=0 — meaning it never bounced (or bounced and came back). With the current broken 'slow' plan it just sits.

OK so let me remove 'slow' and keep 'always' + 'brake'. Let me test.

Actually, let me reconsider whether 'brake' is needed at all. Let me test with only 'always' first (that was the earlier version which got stuck at the step in L2/L3 because 'slow' variants... no, the earlier version had no 'slow' and still got stuck at 5.5 in L2/L3).

Earlier version (dir, delay, chain only): stuck at 5.5 in L2. The candidate dir=1, delay=0, chain=false should climb as analyzed. But it got stuck. Hmm, because re-planning every step: at step 0 it bounces; at step 1 (still airborne) re-plan → the new plan's step 0 might be bounce=false (fine, airborne) or dir=-1... The re-planning each step means the plan is re-chosen from a different state each time, and the chosen candidate's step-0 action might flip.

With COMMIT=22 the plan is stable for 22 steps ✓.

But in the earlier run (no commit) it was stuck. With commit and 'slow' removed, it should work.

Let me test: post ∈ ['always','brake'], COMMIT=22.

Let me also handle: after the commit window, re-planning mid-flight could produce a bad choice. Let's see empirically.

Let me test.

L4 completes ✓ (1 death). L1-3 stuck at the step wall.

So the planner at the wall picks a candidate that doesn't climb. Let me diagnose L2 at x=5.5 specifically with the current candidate set.

Let me print the top candidates there.

All these candidates DO climb and collect (coll=true). The best is delay=130 → bounce at step 130 (0.54 s). With COMMIT=22, we apply steps 0..21 which are dir=1, bounce=false → the ball just presses the wall. Then re-plan → same choice (delay=130) → we apply 22 more steps of nothing → infinite loop, never reaching step 130.

The problem: re-planning with a commit window but the plan's action is deferred beyond the commit.

Fix: score candidates primarily on their behavior within the commit window, or force delay < COMMIT. Simplest: restrict delay ∈ {0, ..., COMMIT-1} ∪ {never}, and re-plan every COMMIT steps. But then a "delay 130" strategy isn't expressible.

Alternative: don't re-plan from scratch; keep the plan and execute it fully (e.g., 130+ steps), re-planning only when the plan is exhausted or the state changed drastically. Let me set COMMIT = 130 (execute the whole plan up to its delay+something) and re-plan after.

Hmm, but a long commit is risky.

Better: make the plan horizon shorter than the commit. E.g., HORIZON=140, COMMIT=40. Then delays ∈ {0,15,30,45,60,80,110,never}. A candidate with delay=130 isn't available; the best available would be within the commit.

But the reason delay=130 wins is the progress term (it climbs later and ends closer to the target). With HORIZON=140 (0.58 s), a candidate with delay=110 would bounce at 0.46 s and barely finish the climb.

Hmm. Let me change the scoring to reward *progress at the commit boundary* more strongly: score = immediate progress (at step COMMIT) * weight + long-horizon outcome. That biases toward acting now.

Let me compute both: dxCommit (progress after COMMIT steps) and dxFull. Score = 2000*survivedFlag + 6000*collectedFull + 10*dxCommit + 3*(d0-d1full) - jamPenalty.

Hmm, "collected" might only happen late.

Let me try: score = survival + 6000*collectedByCommit + 12*(progress toward target measured at COMMIT) + 2*(progress at horizon).

With that, at the wall: candidates with delay=0 climb immediately and collect hoop 8 within ~0.9 s = 216 steps > COMMIT(40)... hmm, the climb takes 0.824 s = 198 steps. So collection wouldn't be captured at COMMIT=40.

OK, different approach: make COMMIT adaptive — commit for `min(plan.delay + 200, HORIZON)` steps, i.e., execute the plan until its key action has happened and settled. Let me set COMMIT = (plan.delay===1e9 ? 60 : plan.delay + 180). That way a delay=130 plan runs for 310 steps ✓ and actually bounces.

Risk: a bad plan runs for 310 steps. But the plan was chosen by simulation, so it should be OK.

Let me try COMMIT = plan.delay===1e9 ? 90 : plan.delay + 200.

Let me test.

Excellent! All four levels are completable by the bot with 0 deaths:
- L1: 16.4 s, 0 deaths
- L2: 16.5 s, 0 deaths
- L3: 21.0 s, 0 deaths, crystal collected too (cry=1)
- L4: 26.0 s, 0 deaths, score 100500

Interesting: L3's bot collected the crystal (cry=1) — the planner found the detour. 

Now let me update test.js with this bot and re-run the full test suite, fixing the other test bugs.

Note L4's final score 100500: let's verify: 6 hoops ×100 = 600, 2 checkpoints ×200 = 400, level clear 500 → 1500 per level (no crystal). 4 levels = 6000. Plus lives bonus 3×1000 = 3000 → 9000. But it shows 100500?! 

Hmm, 100500. That's way more. Something's wrong — maybe the level-clear bonus is being added repeatedly, or the exit is touched multiple times.

Wait: `run.score += 500` on exit, then state='levelclear'. Then Space → next level. In dbg.cjs, after state != 'play' the loop breaks. So the score should be per-level.

L4 alone: score printed is run.score which accumulates across... no, dbg.cjs does loadLevel(3) directly without resetting run.score. run.score was left from the previous level's run (L3 ended at 2500). Hmm, but each dbg.cjs invocation is a fresh process with score starting at 0. loadLevel(3) doesn't reset score. So L4's run.score = 0 + 600 + 400 + 500 = 1500... but it shows 100500.

100500 - 1500 = 99000. Hmm. That's suspicious. 99000 = 99 × 1000? Or... Let me think: maybe the crystal was collected? No, cry=0.

OH — the lives bonus: `if (run.state === 'complete') run.score += run.lives * 1000;` with lives=99 (dbg sets run.lives=99) → 99000 ✓. That explains it. 

So L4 = 600 + 400 + 500 + 99000 = 100500 ✓ consistent.

Good.

Now let me update test.js: use this bot, fix the pad test, the 2-tile wall test, the door test, the crystal tests, and the pads/crumble presence assertions.

Also add a full-run test with the bot: Title → 4 levels → Game Complete with the exact final score.

Expected full-run score with no crystals: 4 × 1500 = 6000, + lives bonus 3×1000 = 3000 → 9000 → "00009000".

Let me also verify the "level clear resets hoops/checkpoints/crystal but not lives/score" behavior.

Let me rewrite test.js.

Also I should double-check the crystal reachability with a better scripted test. Since the L3 bot accidentally got the crystal, let me write a crystal test using the bot with a crystal-seeking target: set the target to the crystal and run the bot. I can extend makeThink to accept a forced target. Let me add an optional `forceTarget` parameter.

Let me restructure: makeThink(G) returns think(forceTarget) — if forceTarget is provided, use the crystal as the target.

Then for each level, run the bot with the crystal as the target and check it collects it (with enough lives/time). That verifies the crystal is reachable ✓ and it's optional (the bot completes levels without it).

Let me implement that.

Let me now write the final test.js.

Also, I should double check the "closed door is impassable" test properly: place the ball approaching the door with velocity and check it stops outside.

And add a test that the exit opens when all hoops are collected.

Let me write the final test.js.

Also: I need to copy bot.cjs content into test.js (self-contained). Let me just have test.js require './bot.js'? For the deliverable, only index.html/style.css/game.js are needed; test.js and gen.js are dev artifacts. I'll keep them (they're harmless) or delete them. The task says everything lives in the current directory and index.html is the entry point. Extra dev files are fine but let me keep the directory clean: I'll keep gen.js and test.js as documented dev helpers? Hmm, "no build step" — gen.js is not used by the game. I think it's cleaner to delete gen.js and test.js at the end... but then I lose the verification artifacts. I'll keep them; they don't affect the game. Actually, a static host would just serve them; harmless. But "no package manager" — no package.json in this dir ✓.

Hmm, test.js requires './game.js' which in a "type: module" parent context fails. Since the parent package.json sets type:module, running test.js needs the /tmp trick. I'll note it. Or I could delete test.js/gen.js from the deliverable directory to avoid confusion. Let me keep them but make them .cjs? Actually let me just delete them at the end after final verification, keeping the deliverable clean: index.html, style.css, game.js. Hmm, but then I can't re-verify. I'll keep them — they're evidence of verification and don't break anything. Actually, a stray `test.js` that errors if someone runs `node test.js` in a module context is a bit sloppy. Let me name them `dev-gen.js`/`dev-test.cjs`... 

Decision: keep `gen.js` and `test.js` but make test.js work standalone by not using require — instead, I'll have test.js read game.js source and eval it? Ugly.

Simplest: name them `tools/gen-levels.js` and `tools/test.cjs` with a local `tools/package.json`? No.

I'll just use `.cjs` extensions for the dev files: `dev/test.cjs` requires `./game.cjs`... but game.js is the deliverable.

OK: test.cjs can do `require('module').createRequire`? Simpler: in test.cjs, read game.js text and run it via `new Function`? Hmm.

Actually: a .cjs file is CommonJS regardless of package.json type ✓. And `require('./game.js')` from a .cjs file — the target `game.js` is resolved by its extension + nearest package.json → "type":"module" → it'd be treated as ESM and require() would fail.

Workaround: in test.cjs, read game.js with fs and evaluate it in a CommonJS context:
```js
const src = fs.readFileSync('./game.js','utf8');
const mod = {exports:{}};
new Function('module','exports','require', src)(mod, mod.exports, require);
```
That works ✓ and keeps everything in one directory. Let me do that. Then I can keep `test.js`... no, test.js would be ESM-parsed. Use `test.cjs`.

Let me name the dev files `dev-test.cjs` and `dev-gen.cjs`. Clean enough.

Let me finalize: I'll write `dev-test.cjs` using the Function trick, and rename gen.js → dev-gen.cjs.

Let me do the final test now.

Let me write dev-test.cjs with the full suite including the bot.

I'll copy the bot code into dev-test.cjs.

Let me write it.

Now write dev-test.cjs that loads game.js via Function and includes the bot inline.

Let me write it.

Note: `physicsStep` is exported ✓. `run.level.crystal` used ✓.

One issue: in the "clearable without touching the crystal" test, the bot might collect the crystal incidentally (as happened for L3 earlier). That test may fail for L3. Let me see.

Also `startRun()` sets state='play' and loads level 0; then loadLevel(i) — loadLevel doesn't change state ✓.

Let me remove bot.tmp.cjs and run.

Good progress. Let me analyze the failures:

1. "air control is weaker than ground control" — my test is wrong: I set grounded=false but vx=6 and holding left (decelerating). Air decel = 7.2 t/s² → from 6 to 5.37 takes 0.0875 s... it reported 0.04 s. Hmm, because `ball.grounded` was set false but the first physicsStep recomputes grounded from the previous landing... Actually I set grounded=false manually, then update → physicsStep uses b.grounded=false → air accel ✓. From 6 to 5.4 at 7.2 t/s² takes 0.083 s = 20 steps. It reported 0.04 s and vx 5.37 — hmm, 6-5.37 = 0.63 → 0.63/7.2 = 0.0875 s = 21 steps. But t reported 0.04. Contradiction... unless the ball landed and became grounded (ground accel 18): 0.63/18 = 0.035 ✓ matches 0.04 s. So the ball became grounded (it was at y=13.5 on the ground → next step it lands → grounded=true → ground accel). My test is flawed. Let me instead test air control by launching the ball upward first (bounce) and then measuring deceleration in the air.

Better test: give the ball a bounce (vy = -V_BOUNCE) so it's airborne, then hold the opposite direction and measure the deceleration rate over 0.2 s → should be ~7.2 t/s².

2. "touching the open door clears the level (+500)" — score 13245 vs expected 12545+400+500 = 13445. Hmm: 13245 = 12545 + 700. The checkpoints: cp0 gave 200 (12545), cp1 gave 200 → 12745. Then hoops: I set all hoops taken=true directly without awarding points, then update → collect() sees them taken → no points. Then exit → +500 → 12745+500 = 13245 ✓. My expected value wrongly assumed +400 for hoops. Fix the expectation: 12545 + 200 + 500 = 13245 ✓. Let me fix the test.

3. "closed door is impassable" — x=54.09. Level 1 exit at col 53; I placed the ball at e.tx-1.5 = 51.5 with vx=5 → it moved to 54.09 → it passed through the door?! The door is at col 53 rows 12,13. The ball at y=13.5 → the door tiles (53,12) and (53,13) are solid when closed. collideX: tile (53,13): dy = 13.5 - 13 = 0.5 → dy >= R → skip! Because the ball's center y=13.5 is exactly at the boundary of row 13's [13,14) — dy = distance from 13.5 to [13,14] = 0 (13.5 is inside [13,14]) → dy=0 → h=0.5 → forbidden [52.5, 54.5] → the ball at 51.5 is not inside → moves right → at 52.5+ it collides → pushed to 52.5. Hmm, but it ended at 54.09.

Wait — maybe the door was open! In this test I did `run.state='play'; loadLevel(0); run.score=0;` — fresh level, hoops not taken → doorOpen=false ✓ closed.

Hmm, but the ball at y=13.5 resting on the ground: row 14 is the ground. The door occupies rows 12,13. The ball spans y [13,14]. Tile (53,13) spans y [13,14) → dy = 0 ✓ → collision should occur at x=52.5.

Unless... the ball's y isn't exactly 13.5. It's 13.5 (resting). Let me check: after `update(DT)` the ball lands → y=13.5 ✓.

Hmm, x=54.09 > 53. Let me reconsider: is `isSolid(53,13)` true? tileAt(53,13) — level 1 row 13 is `..S...O....O..C......O...####.....O......C..O........E..` → index 53 = 'E' ✓. And row 12 index 53 = 'D' ✓. So isSolid returns !doorOpen = true ✓.

So why did it pass? Let me check collideX more carefully. Ball at x=52.4 (moving right), y=13.5, R=0.5.
x0 = floor(51.9) = 51, x1 = floor(52.9) = 52. So the loop only checks tiles 51 and 52! Tile 53 is not in [x0,x1] because x+R = 52.9 → floor = 52. So the ball at x=52.4 doesn't check tile 53. Next step x = 52.4 + 5/240 = 52.42 → still. When x reaches 52.5: x+R = 53.0 → floor = 53 → tile 53 checked: dy = 0 → h = 0.5 → lo = 53 - 0.5 = 52.5, hi = 54.5. Is b.x (52.5) > lo (52.5)? No (strict) → no collision. Next step x = 52.52 → x+R = 53.02 → floor 53 → lo = 52.5, b.x = 52.52 > 52.5 ✓ and < 54.5 ✓ → collision → leftAmt = 0.02, rightAmt = 1.98 → push left → x = 52.5 ✓ vx=0.

So it should stop at 52.5. But it ended at 54.09. So something else happened. Maybe the ball fell? y=13.5... 

OH WAIT. The exit door cells: in level 1, is the ground at row 14 under the door? Row 14 index 53 = '#' ✓ (the row is all '#' except spikes). Yes.

Hmm, let me reconsider: maybe the ball's y drifted. Let me just debug it.

Actually — maybe `run.doorOpen` was true because a previous test in the same process set it? No, loadLevel resets doorOpen=false ✓.

Hmm, but wait: in this test I did `ball.x=e.tx-1.5` = 51.5, `ball.vx=5`. Then `update(DT)` then 200 more updates. 201 steps × 5/240 ≈ 4.2 tiles → 51.5+4.2 = 55.7 if unobstructed; it ended at 54.09. So it did get blocked... at 54.09? That's past the door.

Hmm, 54.09 — maybe it stopped against the world boundary? Level width 56 → out-of-bounds at x=56 → the ball would stop at 55.5. 54.09 isn't that.

Let me debug directly. Possibly the ball bounced up over the door? The door is 2 tiles tall (rows 12,13) sitting on the ground (row 14). The ball rolling at speed 5 hits it... but wait, the ball might have been given vy=0 and grounded=true; the first update lands it. Then it rolls. Hmm.

Unless the ball was at y=13.5 and the door's top is at y=12 — the ball can't go over (needs 2 tiles of rise).

Let me just debug.

4. Level 3 and 4 not completable with 3 lives by the bot (3 deaths). Earlier the bot had 99 lives. So the bot dies 3 times on L3/L4 from a fresh spawn. Hmm — but the "one run clears all four levels" test passed with lives left 5 (it collected crystals). So with 3 lives it sometimes dies.

The bot is imperfect; a human might do better. But I'd like the bot to clear L3/L4 with 3 lives to be confident a human can. Let me look at where it dies.

Actually, note the earlier dbg runs had `run.lives=99` and deaths=0 for L3/L4. Now with 3 lives, deaths=3. Why would lives affect deaths? Because respawn position! With 99 lives, after a death it respawns... but deaths=0 earlier. Hmm, the difference: in the earlier dbg.cjs the bot ran with lives=99 and 0 deaths. Now with startRun() (lives=3) it dies 3 times. The bot's behavior shouldn't depend on lives... unless the planner's simulation differs. Hmm, `physicsStep(DT,true)` doesn't consider lives.

Oh! The difference: in the earlier dbg.cjs I called `loadLevel(idx)` then `run.state='play'`. In dev-test I call `startRun()` (which loads level 0 and sets state play) then `loadLevel(i)`. Same thing.

Hmm, but `plan`, `pk`, `commitVar` are module-level state in the bot that persist across levels! In dbg.cjs each level was a fresh process. In dev-test, the plan carries over from the previous level → the bot starts with a stale plan. That could cause early deaths.

Let me reset the plan when a level starts. I'll add a `resetPlan()` in the test (set plan=null, pk=0) before each botRun.

Also the "one run" test passed with 5 lives (crystals collected) — good.

5. "level N is clearable without touching the crystal" — all failed. Because the bot's target selection sometimes picks the crystal? No — the bot targets hoops/checkpoints. But it may pass near the crystal incidentally. Hmm, all four failed. Let me check: maybe `run.level.crystal.taken` is true because... startRun() → loadLevel(0) → then loadLevel(i) → fresh crystal taken=false. Then botRun(120,false). Hmm.

Wait — `think(false)`: `if(forceTarget) tg = crystal; else ...`. I passed `false` → uses hoops ✓.

So the bot incidentally collected the crystal in all 4 levels? For L1, the crystal is at (32.5,9.5) on the shelf — the bot's route along the ground wouldn't reach it... unless it hops onto the shelf. Possible: when climbing the step at cols 25-28 and hopping, it might land on the shelf.

Hmm, that means my "clearable without the crystal" test is just measuring the bot's incidental route. Not a great test. Let me change it to: the door opens and the level is clearable while the crystal remains uncollected — i.e., verify that the crystal is never required. A better test: check that the crystal's position is not on the critical path — e.g., verify the bot can clear the level with the crystal removed (set crystal.taken = true at level start so it can't be collected and gives no points). Then check the level still completes. That directly tests "never required" ✓.

Let me do that: mark the crystal taken before botRun, then check completion.

6. Final score mismatch: 13000 vs expected 11000. The run collected crystals (lives went to 5 → 2 crystals = +2000). Expected should include crystals: 4*1500 + 2000 (crystals) + lives*1000. Let me compute the expected dynamically: count collected crystals during the run. Let me track: after each level, record whether the crystal was taken. Simpler: compute expected = 4*1500 + 1000*crystalsCollected + 1000*lives. Let me accumulate crystalsCollected.

Let me restructure the full-run test to track per-level crystal collection.

Let me now fix the tests and debug the door issue.

Let me first debug the door.

__dirname is /tmp. Let me use an absolute path.

The door IS impassable ✓. So the earlier test failure (x=54.09) must be because the test ran after the previous test left `run.state='levelclear'` — no, I called loadLevel(0) fresh. Hmm, in the failing test I did:

```
run.state='play'; loadLevel(0); run.score=0;
const e=run.level.exit;
ball.x=e.tx-1.5; ball.y=13.5; ball.vx=5; ball.vy=0; ball.grounded=true;
update(DT); for(let i=0;i<200;i++) update(DT);
```
But `keys` at that point were left over from the previous test — the previous test ended with `hold(false,false,true)`? Let me check: the preceding test block ended with the crystal test which used hold(...) not set... Actually the block before set `ball.x=cr2.x; ball.y=cr2.y; update(DT);` with keys from the earlier spike test. The spike tests used hold(false,false,true) then... Actually the door test comes right after the crystal test block, whose keys were from `hold(false,false,true)` in the "normal bounce clears a floor spike"? No, that's after.

Order in my test file: door test is right after the "touching the open door" test. Before that: checkpoint tests (no hold calls → keys are whatever from the physics section: last was `hold(false,true,true)` in the 4-tile wall test, then the "no corner snagging" test used hold(false,false,true), then determinism used hold(...), then objects section... The objects section never sets keys. So keys could be left as e.g. left=true → the ball moves LEFT.

In the failing run x=54.09 > 51.5, so it moved right. Hmm, with keys.right=true and bounce maybe true → the ball bounces repeatedly → chain hopping → it could hop over the 2-tall door! Bounce height 3 tiles > door height 2 tiles → the ball can bounce over a closed 2-tile door! That's legitimate: the door is 2 tiles tall and a 3-tile bounce clears it.

Hmm! Is that a problem? "It is closed, visibly closed and impassable while any hoop in the current level remains." If the player can bounce over the closed door, then the door isn't impassable — they could exit... but exiting requires *touching* the door. Bouncing over it doesn't touch it (well, the ball would pass beside/over it). Actually if the ball lands on top of the closed door, it touches the door rect → exitTouched() → level complete! That's a bug: you could clear a level without collecting all hoops by landing on top of the closed door.

Wait, exitTouched returns false when !doorOpen ✓. So landing on the closed door doesn't complete the level ✓. But the ball could hop over the door and continue past it. Is that a problem? In L1 the door is at col 53 with ground continuing to col 55. The player could hop over the closed door and then... they'd be stuck at the right wall with the door closed. They'd have to go back. Not a way to skip hoops ✓. But "impassable" is violated in the vertical sense.

Hmm. In my failing test, x=54.09 means the ball got past the door by bouncing over it. That's fine physically but let me reconsider whether it's acceptable. The spec says the closed door is "impassable" — meaning you can't walk through it. Being able to hop over a 2-tall closed door is a bit odd.

Options: make the door 2 tiles tall but also block hopping? The spec says the door is two tiles tall and closed/impassable. Since a normal bounce clears 3 tiles, the player can hop over it. To keep it truly impassable I'd need it 3+ tiles tall, but the spec mandates 2 tiles tall.

I think hopping over the closed door is acceptable — it doesn't let you complete the level, and the door is impassable in the sense that you can't pass through it to reach the exit. Also, in my levels the door is at the far right end with only 2-3 tiles beyond it, so hopping over it is a dead end.

Actually, let me reconsider: could hopping over the closed door let a player skip a hoop? No — the door is the last thing in every level. Fine.

I'll adjust the test to check horizontal impassability (no bounce held).

Now, let me also reconsider: should the closed door be solid at all? Yes ✓.

Now let me fix the remaining test issues:
1. Air control test — redo properly.
2. Door score expectation.
3. Closed door test: release bounce.
4. Reset the bot plan between runs.
5. Crystal-optional test: mark crystal taken before running.
6. Full-run expected score: account for crystals.

Also L3/L4 with 3 lives: after resetting the plan per level, re-test.

Let me update dev-test.cjs.

For the air control test: 
```
run.state='play'; loadLevel(0);
ball.x=6.5; ball.y=10.0; ball.vx=6; ball.vy=-1; hold(true,false,false);  // airborne
measure dv over 0.2 s → expect ~1.44 (7.2*0.2)
```
But the ball will fall and land. Starting at y=10 with vy=-1 → it rises then falls; it stays airborne for ~1.2 s ✓. Measure vx change over 40 steps (0.167 s): expect 1.2 decrease (air) vs 3.0 (ground).

Let me implement: measure the deceleration and assert it's close to ACC_A (7.2) and clearly less than ACC_G (18).

Let me write the fixes.

Also, for the "one run" test, I need to reset the plan too.

Let me apply the edits.

Also the crystal-reachable test uses botRun(120, true) which now resets the plan ✓. But it reported "play t=120.0" for L1-L3 (didn't complete, just ran out of time) yet crystal taken ✓ — fine.

Also the per-level playthrough test (3 lives) — botRun resets the plan ✓.

Let me re-run.

All checks pass. Every level is completable by the bot with 3 lives and 0 deaths, crystals are reachable but optional, and the score math is exact.

Now let me review the rendering code and the browser-side behaviour. A few things to verify:

1. `render()` uses `performance.now()` in drawCrumble ✓ available in browsers.
2. `ctx.ellipse` ✓ supported.
3. The overlay `#overlay:empty { display:none }` — during 'play' the overlay innerHTML is '' → `:empty` matches ✓ hidden. But `updateOverlay` only sets innerHTML when html !== lastCard; when transitioning from a card to play, html='' !== lastCard → sets innerHTML='' ✓ empty ✓.
4. HUD ids: 'level' — I used `document.getElementById('level')` ✓ matches index.html ✓.
5. Canvas 512x512 ✓.

Let me also double-check the camera clamping: `run.cam = clamp(run.cam, 0, l.w - VIEW)` ✓ and levels are wider than 16 ✓.

Camera rendering: `camPx = Math.round(run.cam * TILE)` and tiles drawn at `tx*TILE - camPx` ✓ integers ✓ crisp.

Backdrop columns: `wx = Math.floor(run.cam) + tx` and drawn at `wx*TILE - camPx` ✓ integers ✓.

One issue: `drawCrumble` uses `performance.now()` for jitter — that's frame-rate dependent visual jitter, fine.

Another: in `drawWorld`, `isSolid(tx,ty-1)` for ty=0 → tileAt returns '#' for out-of-bounds → not solid? `isSolid(0,-1)` → tileAt returns '#' → isSolid true → so no top highlight for tiles at row 0 ✓ fine.

Let me now visually verify the rendering by producing a PNG snapshot? I can't run a browser. But I can write a small Node script that emulates the canvas calls... too much. Instead, let me carefully re-read the render code for correctness.

Potential issues:
- `ctx.setTransform(SCALE,0,0,SCALE,0,0)` each frame ✓ resets transform.
- `ctx.imageSmoothingEnabled = false` — irrelevant for vector drawing.
- Hoop post: `ctx.fillRect(cx-0.5, cy+2.7, 1, 2)` — a small post below the ring ✓.
- Checkpoint flag drawing ✓.
- Door open: strokeRect ✓.

Let me also double check the HUD: `elLives.innerHTML=''` then append spans ✓.

One more: `updateHUD` recomputes `hoopsLeft()` which requires run.level ✓ (set at boot via loadLevel(0)).

At boot: `loadLevel(0); run.state='title';` ✓.

Now, one important gameplay check: at the title screen the HUD shows lives=3, level 1, hoops 6 ✓.

Another: after Game Complete → `advance()` → freshTitle() ✓.

Wait: in `advance()`, the 'complete' branch calls freshTitle() ✓. And update() also auto-returns from 'gameover' ✓.

But there's an issue: when the state is 'complete', pressing Space calls advance() ✓.

Also when state==='levelclear', Space → loadLevel(run.levelIndex+1) ✓ and state='play' ✓.

Potential problem: the player is likely holding Space (bounce) when the level completes. `onKeyDown` with e.repeat → returns early after keyDir ✓ so advance() is only called on a fresh keydown ✓. But if the player holds Space through the transition and releases then presses again, fine.

Hmm, but there's a subtle issue: when the level completes while Space is held down, the keydown already fired (it was used as bounce). No repeat-triggering ✓ good.

Another: on the title screen, Space starts the run; the player keeps holding Space → the ball will bounce immediately (bounce held). Harmless.

Now let me double check one more spec item: "Keep a single HUD bar fixed below the 128×128 world viewport so it never hides a map row." ✓ HUD is a separate div below the canvas.

"Do not add objective text, a minimap, tutorial popups or a pause menu." ✓ HUD has lives, level, hoops, score only. The title screen has a one-line control hint ✓ allowed by spec.

Hmm — the HUD shows "LEVEL 1" and "HOOPS 6" — the spec says the HUD contains "one small ball icon per remaining life, the current level number, the number of hoops remaining in this level and the 8-digit score" ✓.

Now let me re-read game.js fully to check for bugs and leftovers.

Also: I should double check the `spikeHit` lethal region for spikes at row 15 (under X blocks in L3/L4). The lethal rect is [tx+0.22, tx+0.78] × [ty+0.5, ty+1] → for ty=15: y [15.5,16] ✓ inside the map ✓.

And the ball falling into a spike pit at row 15 with row 14 gone: the ball falls from center 13.5; the ground below is... nothing at row 15 (spike, not solid) → it keeps falling to y=16 (out of bounds = solid) → it would rest at center 15.5 → but it dies on the way ✓.

Let me verify the death happens: at center y=15.0, distance to the lethal rect (dy = 15.5-15.0 = 0.5, dx=0 if x aligned) → 0.5 < 0.5? No, `dx*dx+dy*dy < rad*rad` → 0.25 < 0.25 false → not dead at exactly 0.5. At y=15.01 → 0.2401 < 0.25 ✓ dead. And the ball continues to fall to 15.5 → dead ✓. Good.

Now let me read through game.js once more for consistency.

Also I realize: `run.level.map` is the original string array; `validateLevel` checks ragged rows ✓.

Let me read the file.

Looks good. One concern in collideX: when `vx === 0` and the ball is exactly in the middle, the shortest-way-out rule handles it. Fine.

Another concern: in collideX, when the ball is pushed to `hi` (right side) while moving right — that could teleport it through a thin wall. But penetration is tiny (max 14*dt = 0.058 tiles), so `leftAmt` will be small and `rightAmt` large → pushed back ✓. Only if the ball were deep inside a tile would it pick the far side. With max penetration 0.058 and h ≥ 0, lo = tx - h. If the ball is at tx - h + 0.058 → leftAmt = 0.058 ✓ small ✓.

Hmm, one edge: if h is very small (the ball grazing a corner), lo ≈ hi ≈ tx+0.5... no: lo = tx - h, hi = tx+1+h. If h ≈ 0, lo = tx, hi = tx+1. The forbidden interval is [tx, tx+1] — the ball center inside means it's within the tile's x-range but just barely touching in y. leftAmt = b.x - tx (could be up to 1), rightAmt = tx+1-b.x. It picks the nearer side ✓ reasonable.

Now let me read the rest.

One issue: in `physicsStep`, when the ball lands on a crumbling block that is in 'tell' state, `triggerCrumble` only fires for 'idle' ✓. But if the ball lands on a block already in 'tell', the timer continues ✓ good.

Another: `b.grounded = !!land` — if the ball is pushed *down* out from under a tile (the `else` branch), land is null → grounded false ✓.

Potential issue: a ball resting on a crumbling block that becomes 'gone' — next step, no collision → grounded=false → falls ✓.

Another: `if (land.vy > 2.0) b.squash = ...` ✓.

Now, one gameplay concern: the pad launch happens on every landing on a pad, including when the ball lands back on the pad after a pad jump. That's intended.

Another: `keys.bounce` is checked at landing ✓.

Now let me read the rest (update, camera, render, HUD, input, boot).

One issue: the backdrop columns are drawn at `wx*TILE - camPx` where `wx = Math.floor(run.cam) + tx` — but `camPx = Math.round(run.cam*TILE)`. If run.cam = 3.6, floor = 3, camPx = 29 (3.6*8=28.8→29). wx=3 → px = 24-29 = -5 ✓ consistent with the tile drawing (which uses tx*TILE - camPx) ✓. Good.

Another: the spike drawing — `moveTo(x+0.5, py+1)` then `lineTo(x+TILE/3-0.5, py+TILE)` and `lineTo(x, py+TILE)`. Slightly odd triangle but fine visually.

Now let me check the remaining part (drawCrumble onwards) and the boot.

Also I want to double check the visual distinctness: crumbling blocks use `pal.crumble` which differs from `pal.block` ✓ plus cracks ✓.

Let me read the rest.

A few refinements to consider:

1. `module` is not defined in a browser → `typeof module !== 'undefined'` ✓ safe.

2. The title screen: the canvas is a flat dark color and the overlay card covers the middle. Good.

3. `advance()` on 'gameover' does nothing ✓ (auto after 2 s).

4. Potential issue: when the level completes, `run.state='levelclear'` but the world keeps rendering the last frame ✓ good (the card overlays it).

5. `updateHUD` includes run.state in the key so lives icons update ✓.

6. One thing: the HUD shows 5 life slots always (3 filled at start). The spec says "one small ball icon per remaining life". Showing 5 slots with 3 lit is arguably showing more icons than lives. Let me render exactly `run.lives` icons instead. That's more literal. Let me change to render exactly `lives` icons (max 5).

7. The `hint` line uses ` ` — fine.

8. `drawCheckpoint` draws inactive checkpoints too ✓ (they're visible objects).

9. Ball visibility: red circle with a dark outline on all four palettes ✓. Level 3's block is purple (#5b3fa8) and crumble #7a5ac0 — red ball stands out ✓. Level 4 block #263449 ✓.

10. Hoop color gold #ffd23f vs crystal violet ✓ distinct.

11. One more: the spec says "at most a one-logical-pixel outline". The hoop stroke is 1.6 logical px — slightly over. Let me set lineWidth 1.5 → still >1. Let me use 1.5? "at most a one-logical-pixel outline" — I'll set the hoop lineWidth to 1.5... hmm, better to comply: use 1.0? A 1-logical-px ring at 4x = 4 device px, visible ✓. Let me use 1.5 for readability... I'll comply strictly: 1.25? Let me just use 1.5 → that's 1.5 logical px which exceeds "at most one". Let me set it to 1.0 and radius 2.6 — a thin ring. At 4x scale that's 4 device px thick — clearly visible ✓. I'll use 1.

Actually the ball outline is lineWidth 1 ✓. The checkpoint flag is a filled shape ✓. The door open outline is 1 ✓. The gone-block outline is 1 ✓. Let me change the hoop to 1.

Hmm, a 1-logical-px ring might look thin but it's fine and matches the "flat, geometric, high-contrast" brief. Let me use 1.25 as a compromise? No — strictly 1.

Let me make it 1.

12. Also `ctx.lineWidth = 1` in the scaled transform = 1 logical px = 4 device px ✓.

13. Another consideration: the death fragments use `f.size * (f.life/DEATH_TIME) * 2.2` → they shrink over time. "expanding-fragment burst" — the fragments expand outward (position) ✓ but shrink in size. Let me make them expand in size instead: size grows as life decreases? "expanding-fragment burst" likely means the burst expands. Position expansion ✓. I'll make the fragment size constant-ish and slightly growing. Let me use `s = f.size * 1.6 + (1 - f.life/DEATH_TIME) * 1.2` — grows slightly. Actually simpler: keep them a fixed small square; the burst expands. I'll make them grow slightly for a nicer effect.

Let me change to: `const s = f.size * 1.4 + (1 - f.life/DEATH_TIME) * 1.5;`

14. Also, the fragments should be visible for the full 0.4 s ✓.

15. `run.cardT` for 'levelclear' isn't used to auto-advance ✓ (Space required) ✓.

16. One more spec check: "Clearing a level shows a brief Level Complete card ... which continues to the next level on Space." ✓

17. "Running out of lives at any point produces Game Over and then a fresh title screen." ✓

18. Check: at Game Over, `freshTitle()` resets lives/score and loads level 0 ✓.

19. Potential problem: `freshTitle()` is called from `update()` while iterating; it calls loadLevel(0) which is fine.

20. Another: after Game Complete, pressing Space → freshTitle ✓.

Let me also double check: `advance()` for 'title' calls startRun() which sets lives=3, score=0, loadLevel(0), state='play' ✓.

21. Numpad keys: e.code for numpad 4 is 'Numpad4' ✓ but only when NumLock is on; with NumLock off it's 'ArrowLeft'. Let me also map 'ArrowLeft' etc. ✓ already. Good enough.

22. preventDefault on Space prevents page scroll ✓. Also arrows ✓.

23. One more: the game should have focus — the listener is on window ✓ always.

Let me make the small edits: lives icons count, hoop lineWidth, fragment size.

Also, I realize there might be an issue with the HUD `#lives` when lives is 0 (during gameover) → 0 icons ✓ fine.

Let me apply the edits.

Additionally, let me reconsider one gameplay risk I noticed: the player can bounce over the closed exit door. In L1 the door is at col 53 and the level ends at col 55. If a player hops over the closed door they land on cols 54-55 and are stuck against the right wall; they can hop back ✓ not stranded.

Another risk: in L4, the exit is at col 70 and the level ends at 71. Fine.

One more important check: are there any places where the ball could get permanently stuck (not escapable)? 
- L1: the right end (cols 54-55) — the ball can bounce back left over the door ✓ (door is 2 tall, bounce 3 ✓).
- L2: the pocket between the pad (22-23) and the plateau (26) → cols 24-25 ground; the ball can roll back left ✓ escapable.
- L2: after the plateau, cols 34-40 ✓ open.
- L2: the pocket between the spike field (50-54) and... the ball lands at 55+ ✓.
- L3: the pit at 16-18 ✓ escapable (tested).
- L3: cols 34-40 ✓.
- L4: cols 18-21 (between pad and plateau) ✓ open ground, can walk back to the pad ✓.
- L4: cols 48-50 (before pad 51-52) ✓ open.
- L4: on the solid block 60-63 ✓ can go back left onto the bridge (when restored) or drop right at col 66? At col 63 the ball's right edge... the block spans cols 60-63 (x 60..64). The ball at center 63.5 is supported. Moving right past 64.5 → falls; below at col 64 is the X bridge (row 9) if present → lands on it ✓; if gone → falls to spikes at row 14 col 64 → death (not stranded). ✓
- L4: cols 66-71 ✓ open.

Good.

One more: L4's spike field at 53-55 — could the player end up standing at col 53-55? No, they'd die.

Now, another important check: the crumbling blocks in L4 at cols 36-39 (row 14) over spikes at row 15. If all four collapse and the player is at col 40 (ground) wanting to go back left, they'd need to cross the gap → they can wait for restoration ✓ (3 s). And they're not stranded since they can wait on the ground ✓.

OK. Let me also think about whether the crumbling blocks could collapse while the ball is resting on them in a way that traps it — no, it falls.

Let me apply the small polish edits and then do a final visual sanity check by rendering the game to a PNG using a headless canvas? Not available. Instead, let me write a tiny ASCII renderer in the dev harness to eyeball the level layouts with objects — I already have the maps printed. Good enough.

Actually, one more valuable check: verify that the camera never reveals out-of-bounds space. cam clamped to [0, w-16] ✓ and w ≥ 56 > 16 ✓.

Let me apply the polish edits.

Now let me do a final visual sanity check by writing a tiny software rasterizer that mimics the canvas calls and outputs a PNG/PPM so I can eyeball a frame. That's a fair amount of work but valuable to confirm the rendering isn't broken (e.g., objects off-screen).

Alternative lighter check: simulate a frame and assert that all drawn primitives fall within the canvas bounds and that key objects (ball, hoops, door) are drawn at plausible positions. I can instrument by monkey-patching ctx.

Let me do a simple instrumented render: create a fake ctx that records calls, run render() with a stub document/window, and check the recorded calls. That verifies render() doesn't throw and produces sensible coordinates.

To do that I need to run game.js in a fake DOM environment. I can provide globals: `document`, `window`, `requestAnimationFrame`, `performance`. Let me build a minimal stub in the dev harness:

```js
const calls=[];
const ctxStub = new Proxy({}, {get:(t,k)=> (k==='canvas')?canvasObj: (...args)=>{calls.push([k,args]);}});
```
But `ctx.fillStyle = x` is a set → Proxy set handler ✓. And `ctx.setTransform(...)` ✓.

document stub: getElementById returns fake elements with innerHTML/textContent/appendChild/width/height/getContext.

window stub: addEventListener, etc.

requestAnimationFrame: capture the callback; call it a few times with increasing timestamps.

This will exercise render(), updateHUD(), updateOverlay(), input handlers, and the main loop. Very valuable: it catches runtime errors in the rendering path (which the Node physics tests never touch).

Let me add that to dev-test.cjs as a "render smoke test".

Let me write it.

Elements need: canvas.width/height settable, getContext('2d') → ctxStub; lives/level/hoops/score elements with innerHTML/textContent; overlay with innerHTML.

For `elLives.appendChild(d)` where d = document.createElement('span') → need createElement returning an object with className ✓.

Let me implement.

Also `window.addEventListener('keydown', fn)` — I can then simulate keydowns to test input handling and screen flow (Space → start).

Let me write this smoke test.

Note: game.js's boot block requires `document` at load time. In this harness I define global.document before loading ✓. But `window.addEventListener` is used ✓. `requestAnimationFrame` global ✓ — game.js calls bare `requestAnimationFrame(frame)` ✓ global.

Also `performance.now()` ✓ global.

One issue: game.js's boot calls `requestAnimationFrame(frame)` — my stub stores it ✓.

`tick(16)` calls frame(tNow) which calls `render()` → uses ctx from the canvas stub ✓.

`els.game.getContext()` returns a NEW ctx each call — but game.js calls getContext once at boot ✓.

Hmm: `makeEl.getContext(){ return makeCtx(); }` returns a new proxy each call; called once ✓.

The `ctx` proxy: `ctx.setTransform(...)` → get('setTransform') → not in state → returns rec ✓. `ctx.fillStyle = x` → set ✓. `ctx.imageSmoothingEnabled = false` → set ✓. `ctx.beginPath()` ✓.

Potential problem: `ctx.lineWidth = 1` then later `ctx.lineWidth` read? Not read ✓.

Another: `drawCalls.some(c=>c[0]==='strokeRect')` — strokeRect is used for the open door and gone crumbles. At level 1 start, the door is closed → no strokeRect. Hmm, that assertion may fail. Let me check: in level 1 there are no crumbling blocks, and the door is closed → no strokeRect calls. So the assertion fails.

Let me change that assertion: check `arc` calls >= 8 (6 hoops + 1 crystal = 7 arcs... hoops 6 arcs + crystal 2 arcs = 8 ✓). And check that fillRect calls include the door (hard to distinguish). Let me just check arcs and drop strokeRect.

Also "nothing is drawn outside the 128x128 logical viewport": my filter flags x<-40 or x>172 or y<0 or y>132. Tiles are drawn at tx*TILE - camPx which can be as low as -16 (t0 = floor(camPx/8)-1) and as high as (t0+18)*8 - camPx ≈ 128+16 = 144. So x can be up to ~144 and down to -16 ✓ within my bounds. y from 0 to 120 ✓. The ball ellipse at cx could be off-screen if the ball is near the camera edge — but the camera follows the ball so it's near the centre ✓. Hoops/objects drawn off-screen: `for (const h of l.hoops)` draws ALL hoops regardless of visibility → cx can be far off-screen (e.g., x = 400). That's inefficient but harmless. My assertion would flag it.

Let me cull off-screen objects in drawWorld for efficiency (good practice) and then the assertion holds. Let me add culling: skip objects whose cx is outside [-16, 144].

Let me add that to game.js.

Also the fragments: `f.x*TILE - camPx` could go off-screen ✓ flagged. Let me include them in the culling or relax the test bounds. I'll cull objects and let fragments be (they're short-lived and near the ball). Actually fragments fly outward up to ~7 t/s * 0.4 s = 2.8 tiles = 22 px from the ball, which is near the camera centre → within bounds ✓.

Let me add culling for hoops/checkpoints/crystal/exit.

Then the assertion: fills with x < -40 or x > 172 → none ✓.

Let me apply.

Also the backdrop columns: `wx*TILE - camPx` for wx in [floor(cam)-1, floor(cam)+17] → px range ≈ [-24, 152] ✓ within -40..172 ✓.

Let me edit game.js to cull, then run the render test.

Also cull crumble/spike/block tiles — already culled by the t0..t1 loop ✓.

Also the `strokeRect` assertion — let me change it to check that the door is drawn (fillRect with doorClosed color). Simpler: check `arc` count >= 8 and that a `stroke` call exists (hoops use stroke) ✓.

Let me update the test assertion.

Also note: the crumble 'gone' state uses strokeRect; in level 1 there are none. Let me change the assertion to `drawCalls.some(c=>c[0]==='stroke')`.

Let me edit dev-render.cjs and run.

Note: the "camera stays inside the level bounds" test uses `G.loadLevel(0)` earlier — it's after the live play section which loaded level 0 ✓.

Also the frame-rate independence test: `runAt` calls `G.startRun()` then `G.loadLevel(1)`. But `G.keys` are set inside the loop ✓. The loop: `n = max(1, round(DT/(frameMs/1000)))` — for 16.7ms → round(0.004167/0.0167) = round(0.2495) = 0 → max(1,0)=1 ✓; for 8.3ms → round(0.5) = 1 (Math.round(0.5)=1) ✓; for 33.3ms → round(0.125)=0 → 1 ✓. So all run 1 step per iteration ✓ identical. That's a weak test (it just confirms the fixed step). Fine — it demonstrates the accumulator independence. Let me make it stronger by simulating the actual accumulator loop from `frame()` at different frame cadences.

Better: replicate the accumulator: for a given frameMs, run the equivalent of frame(): acc += frameMs/1000; while(acc>=DT) update(DT). Over 6 seconds of simulated wall time, the number of physics steps is the same (floor(6/DT)) as long as we account for the leftover acc. The final ball state after the same number of steps should be identical. Let me implement:

```
function runAt(frameMs){
  startRun(); loadLevel(1); state='play';
  let acc=0, wall=0;
  while(wall < 6){
    const f = frameMs/1000;
    acc += f; wall += f;
    while(acc >= DT){ 
      keys.right=true; keys.bounce = (Math.floor(wall*4)%2)===0;  // input depends on wall time -> differs!
      update(DT); acc -= DT;
    }
  }
}
```
Input keyed on wall time would differ between cadences. Instead key the input on the physics step index → identical ✓. Then the number of steps = floor(6/DT) which differs slightly by cadence (leftover acc). To compare, run a fixed number of physics steps and compare — that's the same as before.

The real point: physics is identical at different refresh rates because it's driven by a fixed accumulator. I'll test: run the accumulator at 30/60/120 fps for the same wall time and compare the state after the *same number of physics steps* — trivially equal. 

Better test: verify that the accumulator produces the same number of steps per wall-second regardless of cadence, and that the trajectory sampled at fixed wall-clock checkpoints matches. Let me do: for each cadence, run the accumulator for 6 s of wall time, recording the ball state each time the accumulated physics time crosses a 0.25 s boundary. Compare those samples across cadences. The number of steps to reach 0.25 s is exactly 60 for all cadences ✓ so samples match ✓. That's a meaningful test of the accumulator.

Let me implement that.

Let me rewrite that block.

Wait — `G.update(DT)` in the 'play' state also calls followCamera, and the death state changes things. If the ball dies, samples differ. Level 2 (index 1) with keys.right=true and bounce every 30 steps... it may die. Let's see; if it dies the samples could still match across cadences (deterministic) ✓. Fine.

Let me run both harnesses.

Two failures:

1. "title card carries a one-line control hint" — my assertion counted `<p` occurrences === 3, but there are 2 `<p>` tags. Fix the assertion: expect exactly 2 `<p>` (press + hint) and that the hint contains 'roll left' and 'bounce'.

2. Step count differs across cadences (1444 for one of them). That's expected: with a leftover accumulator, the total steps over 6 s of wall time differ by at most 1 between cadences. 1444 vs 1440 (6/DT = 1440). At 60fps: 360 frames × 1440/360 = 4 steps each = 1440 exactly. At 120fps: 720 frames, each 1/120 s = 2 steps exactly → 1440. At 30fps: 180 frames × 8 steps = 1440. Hmm, so why 1444?

Because `wall < 6` loop: at 30fps, frames are 1/30 = 0.03333 s; 180 frames = 6.0 s exactly (floating point may give 181 frames). The reported a.n is 1444 — that's 4 extra steps, meaning ~1 extra frame. Floating point accumulation of `wall += f` can overshoot slightly, adding an extra frame.

The important test is that the sampled states match ✓ (they do). Let me relax the step-count assertion to allow a difference of ≤ 8 steps (one frame's worth) — or better, compare samples only. Let me change the assertion to: step counts differ by at most one frame's worth of steps.

Actually the cleanest statement: "the simulation advances the same number of fixed steps for the same amount of simulated time" — which the sample test proves. Let me change the first assertion to check that the step counts are within 8 of each other and each ≈ 1440.

Let me fix both assertions.

Also the Level Complete card showed score 00000100 — that's from the earlier live-play section (one hoop collected). Fine.

Let me re-run both harnesses.

Also, I noticed the Level Complete card in the flow test says "LEVEL 1 COMPLETE" while levelIndex was 0 ✓.

Let me run.

Everything passes. Now a few final polish items:

1. Level 1 should be "the gentlest" and open on flat ground with no hazard on the first screen ✓ (spikes at 16-17, first screen is cols 0-15).

2. Level 4 should be the hardest ✓ (pads + crumbling bridges + a longer, tighter final stretch).

3. "Level 3 introduces crumbling blocks, with at least one crossing on the critical path" ✓ (cols 30-33 X over spikes; the ground path is blocked there).

Wait — is the L3 X crossing at cols 30-33 truly on the critical path? The X blocks are at row 14 (the surface). If they collapse, the spikes at row 15 are exposed. The player must cross cols 30-33. Can they bounce over the whole 4-tile stretch? A max-speed hop covers 6.2 tiles → from 29.5 they'd land at 35.7 ✓ on the ground past the crossing. So it's crossable without using the blocks. Hmm — "with at least one crossing on the critical path" — the crossing IS on the critical path (it's the floor you run over), even if a skilled player could hop over it. I think that satisfies it: the crumbling blocks are part of the required route's floor. But to be safer, let me widen that crossing so hopping over it isn't trivially possible... Actually being able to hop over it is a nice alternative route, not a problem. But the requirement says "at least one crossing on the critical path" — meaning the player must interact with crumbling blocks on the way. In L3, the raised bridge at cols 48-50 (row 12) IS required: the ground below is spikes at row 14, and the step at 46-47 leads onto the bridge. Can the player hop from the step top (center 47.5, y 11.5) over the 3-tile bridge (x 48..51) and land at col 51 (ground, y=14)? A hop from 47.5 at speed 6: rise 3 → the ball's bottom goes from 12 to 9; it lands when its bottom returns to 12 at 6.2 tiles → x = 53.7 → but wait, it would land on the ground at y=14 only if nothing blocks. At x=51+ the ground surface is y=14; the ball descending: its bottom reaches 12 at x=53.7 (still above the ground), continues falling to bottom=14 → x = 53.7 + (extra). Let me compute: from apex (bottom 9) falling to bottom 14 = 5 tiles → t = sqrt(2*5/22) = 0.674 s → x = 47.5 + 6*(0.824+0.674) = 47.5+8.99 = 56.5 → col 56 which is... spikes at 57-58? col 56 is ground ✓. Hmm, so the player could hop from the step over the raised bridge and land at col 56 on the ground! That skips the crumbling bridge.

Hmm, but wait: at x=53.7 the ball's bottom is at 12; the ground at cols 51-56 is at y=14, so it keeps falling; at x=56.5 it lands ✓ safe. So the raised crumbling bridge can be bypassed with a full-speed hop from the step.

Is that a problem? The requirement: "Level 3 introduces crumbling blocks, with at least one crossing on the critical path." The first crossing (cols 30-33 at ground level) — can it be bypassed? From col 29.5 at speed 6, a hop lands at 35.7 ✓ on the ground (34-40) ✓ bypassable too.

Hmm. So neither L3 crossing is strictly mandatory. But they are literally part of the floor of the critical path — the player runs over them at ground level for crossing 1 (they'd only hop if they chose to bounce). For crossing 1, the natural route IS running across the crumbling blocks (they form the floor). I'd say that satisfies "a crossing on the critical path".

But to be safe and more faithful, let me make crossing 1 in L3 genuinely require the crumbling blocks: make it wider so a single hop can't clear it, forcing the player to run across the blocks. E.g., 6 blocks wide (cols 30-35) over spikes. A max-speed hop from 29.5 covers 6.2 tiles → lands at 35.7 → col 35 is an X block (solid) ✓ lands on the block ✓. So they'd land on the crumbling block and then must keep running across it ✓ that forces interaction ✓.

Hmm, landing on a crumbling block is fine — it starts collapsing 0.5 s after landing, and the player at speed 6 covers 3 tiles in 0.5 s ✓ safe.

Let me widen crossing 1 to cols 30-35 (6 blocks) with spikes at row 15 under them, and move the ground after to 36-40. Then the player must cross 6 tiles of crumbling blocks. Run-up from 27-29 (3 tiles) → reaches max speed ✓ crossing 6 tiles takes 1.0 s at speed 6. Each block collapses 0.5 s after first contact, chasing the player ✓ safe at speed.

But if the player enters slowly (say 2 t/s), they'd take 3 s and fall in → death → respawn at checkpoint 28 ✓. That's the intended challenge, and it's fair (the checkpoint is right before).

Hmm, but "no obstacle that has to be taken at exactly one speed" — speeds ≥ ~3.5 t/s work (need to advance ≥ 0.5 tile per 0.5 s relative to the collapse chase... let me think: the block the player is standing on collapses 0.5 s after they first touched it. If the player moves at speed v, they leave a block after 1/v seconds. If v ≥ 2, they leave each block within 0.5 s ✓ safe. Actually they must leave block k before block k collapses, i.e., within 0.5 s of first touching it → 1/v ≤ 0.5 → v ≥ 2 t/s ✓ generous.

Hmm, but there's a subtlety: the ball is a circle of radius 0.5, so it's "on" a block over a 1.5-tile span. Roughly the same.

So speeds ≥ 2 work ✓ generous ✓.

Let me widen crossing 1 to 6 blocks. Then the ground after is cols 36-40 (5 tiles) and the hoop at 36 ✓, spikes at 41-42 ✓, checkpoint 44 ✓.

Wait, currently: X at 30-33, spikes row 15 at 30-33, ground 34-40, hoop 36, spikes 41-42, ground 43-45, checkpoint 44, step 46-47, X bridge 48-50, spikes row 14 at 48-50, ground 51-56, hoop 53, spikes 57-58, ground 59-63, exit 62.

New: X at 30-35, spikes row 15 at 30-35, ground 36-40 (hoop 38), spikes 41-42, ground 43-45 (checkpoint 44), step 46-47, X 48-50, spikes 48-50, ground 51-56 (hoop 53), spikes 57-58, ground 59-63 (hoop 60), exit 62.

Check the landing after crossing: the player runs off col 35 onto col 36 ✓ ground ✓.

And can they hop over the 6-tile crossing? From 29.5 at speed 6 → lands at 35.7 → col 35 is an X block ✓ (lands on the last block, then must keep moving; it collapses 0.5 s later, they're off ✓). Or from 28.5 → lands at 34.7 → col 34 (X) ✓. Either way they land ON the crumbling bridge ✓ forced interaction ✓.

Good. Let me also double check the checkpoint at 28 is right before ✓.

Similarly for L4, the crossing at 36-39 (4 blocks) — from col 35 at speed 6, a hop lands at 41.2 → col 41 is ground ✓ bypassable. Let me widen L4's first crossing to 6 blocks (36-41) with spikes at row 15 under them, ground 42-45. Then a hop from 35.5 lands at 41.7 → col 41 is X ✓ forced ✓. Then ground 42-45, spikes 46-47, checkpoint 49...

Hmm wait, L4 currently: X 36-39 over spikes row 15; ground 40-45; hoop 43; spikes 46-47; ground 48-50; checkpoint 49; pad 51-52; spikes 53-55; X bridge 56-59 row 9; spikes row 14 at 56-59; solid 60-63; hoop 61; X 64-65 row 9; spikes row 14 at 64-65; ground 66-71; hoop 68; exit 70.

New: X 36-41 (6 blocks), spikes row 15 at 36-41, ground 42-45, hoop 43 ✓, spikes 46-47, ground 48-50, checkpoint 49, pad 51-52, ...

Check the hop: from col 35 (center 35.5) at speed 6 → lands at 41.76 → col 41 = X ✓ forced onto the bridge ✓. From 34.5 → 40.76 → col 40 = X ✓. Good.

Also the player could run onto the bridge at col 36 ✓.

Now, does widening break the "leave room" rule? Before the crossing: ground 30-35 (6 tiles) after the plateau drop. The player drops off the plateau at col 29 (center 28.5) and lands around col 32-33 ✓ clear ✓. Checkpoint at 30 ✓.

Hmm, the checkpoint at 30 is under the crystal shelf ✓.

Let me also reconsider L4's high crumbling bridge at 56-59 (4 blocks at row 9): can it be bypassed? The player arrives via the pad; they land on the bridge. Could they land past it? Takeoff at 52.5 max → lands at 58.74 → col 58 = X ✓ on the bridge. Takeoff at 51.5 → 57.74 ✓. So they always land on the bridge ✓ forced ✓.

And the X at 64-65 (2 blocks at row 9): the player runs from the solid block at 60-63 across them ✓ forced (the ground below is spikes) ✓.

OK, let me update the level data for L3 and L4.

Also, for L3's raised bridge (48-50), it's bypassable by a hop — that's fine since crossing 1 is now mandatory.

Let me regenerate the maps. I need to recreate gen.js... I deleted it. Let me just directly edit the map strings in game.js.

L3 row 14 currently: `################XXX######^^###XXXX#######^^#####^^^######^^#####`
Indices: 0-15 '#', 16-18 'X', 19-24 '#', 25-26 '^', 27-29 '#', 30-33 'X', 34-40 '#', 41-42 '^', 43-47 '#', 48-50 '^', 51-56 '#', 57-58 '^', 59-63 '#'.

New: 30-35 'X', 36-40 '#'. So: `################XXX######^^###XXXXXX#####^^#####^^^######^^#####`
Let me count: 16 '#' (0-15) + 'XXX' (16-18) + '######' (19-24) + '^^' (25-26) + '###' (27-29) + 'XXXXXX' (30-35) + '#####' (36-40) + '^^' (41-42) + '#####' (43-47) + '^^^' (48-50) + '######' (51-56) + '^^' (57-58) + '#####' (59-63) = 16+3+6+2+3+6+5+2+5+3+6+2+5 = 64 ✓

Row 15 currently: `##############################^^^^##############################` → 30 '#' (0-29) + '^^^^' (30-33) + 28 '#' (34-63) = 64 ✓
New: 30 '#' + '^^^^^^' (30-35) + 28 '#' (36-63) = 30+6+28 = 64 ✓ → `##############################^^^^^^##########################`

Row 13 currently: `..S.O.####............O.....C.......O.......C.##.....O......O.E.`
Indices: S 2, O 4, #### 6-9, O 22, C 28, O 36, C 44, ## 46-47, O 53, O 60, E 62.
Hoop at 36 → col 36 is now ground ✓ (36-40 ground) ✓ keep.

So row 13 unchanged ✓.

L4 row 14 currently: `#############^^#PP##################XXXX######^^###PP^^^^^^^####^^######`
Indices: 0-12 '#', 13-14 '^', 15 '#', 16-17 'P', 18-35 '#', 36-39 'X', 40-45 '#', 46-47 '^', 48-50 '#', 51-52 'P', 53-59 '^', 60-63 '#', 64-65 '^', 66-71 '#'.
New: 36-41 'X', 42-45 '#'. → 0-12 '#' (13), 13-14 '^^' (2), 15 '#' (1), 16-17 'PP' (2), 18-35 '#' (18), 36-41 'XXXXXX' (6), 42-45 '####' (4), 46-47 '^^' (2), 48-50 '###' (3), 51-52 'PP' (2), 53-59 '^^^^^^^' (7), 60-63 '####' (4), 64-65 '^^' (2), 66-71 '######' (6) = 13+2+1+2+18+6+4+2+3+2+7+4+2+6 = 72 ✓

Row 15 currently: `####################################^^^^################################` → 36 '#' (0-35) + '^^^^' (36-39) + 32 '#' (40-71) = 72 ✓
New: 36 '#' + '^^^^^^' (36-41) + 30 '#' (42-71) = 72 ✓ → `####################################^^^^^^##############################`

Let me count the new string: 36 '#' then 6 '^' then 30 '#'. 
36 '#': "####################################"
6 '^': "^^^^^^"
30 '#': "##############################"
Total 72 ✓

Let me apply these edits and re-run the tests.

Also I should double check L3's hoop at 36: after the crossing, the player runs off col 35 (X) onto col 36 ✓ ground ✓ collects the hoop ✓.

And L4's hoop at 43 ✓ ground (42-45) ✓.

Let me apply.

Now I need to verify the L3 crossing: the player runs onto X at col 30 from ground at 29. But wait — the checkpoint at 28 and the spikes at 25-26. The player hops over 25-26 from ~23.3 and lands at ~29.5 → col 29 is ground ✓ then immediately onto the X bridge at 30 ✓.

Hmm, landing at 29.5 and then running onto the bridge: the first X contact at col 30 (the ball touches X when its center reaches 29.5, since the circle overlaps tile 30's x-range [30,31] when center > 29.5). So the collapse timer starts almost immediately ✓ and the player must already be at speed ✓.

Is that fair? The player lands at 29.5 (from the hop) with speed ~6 ✓ and crosses 6 tiles in 1 s ✓ each block collapses 0.5 s after contact ✓ safe.

But if the player lands at 29.5 with low speed (e.g., they bounced slowly), they'd be in trouble. The checkpoint at 28 is right there ✓.

Hmm, one risk: the player lands at 29.5 and the ball's support — col 29 is ground ✓.

Let me re-run the tests to confirm the bot still clears L3 and L4.

Also let me double check the L4 crossing: the player runs from col 35 (ground) onto X at 36 ✓. Or they hop and land on the X ✓.

Let me run the tests.

Two problems:
1. "LEVEL EMBER PROBLEMS: ragged row" — my L3 row 15 edit produced a wrong length. Let me check.
2. L4 now fails — the widened crossing broke the bot's route (or the level).

Let me check the L3 row lengths.

Row 14 new: `################XXX######^^###XXXXXX#####^^#####^^^######^^#####`
Count: 16+3+6+2+3+6+5+2+5+3+6+2+5 = 64 ✓
Row 15 new: `##############################^^^^^^##########################` → 30+6+28 = 64? Let me count the trailing '#': I wrote 26? Let me count programmatically.

Let me write a quick check of all row lengths.

For L4: the widened crossing at 36-41 means the player must cross 6 crumbling blocks. Why does the bot fail now? Possibly because the bot lands on the bridge at low speed, or the landing point is near the end and it dies. Let me debug L4.

Let me first fix the row lengths, then debug L4.

Actually, maybe widening to 6 is too much for the bot's planning horizon (420 steps = 1.75 s). Crossing 6 tiles at speed 6 takes 1 s ✓ within the horizon. Hmm.

Let me debug L4 with the bot and see where it dies.

Let me first fix lengths.

EMBER row 15 is 62 — I need 64. Let me fix: 30 '#' + 6 '^' + 28 '#' = 64. My string had 26 trailing '#'. Let me rewrite it properly.

Let me generate the exact string.

My L3 row 14 was correct; row 15 needs 28 trailing '#' (I had 26). Let me fix.

Then debug L4.

Wait, the L4 row 15 generated is `####################################^^^^^^##############################` = 36+6+30 = 72 ✓ and my edit already used that ✓.

Now debug L4 with the bot. Let me re-run the dbg harness (I need to recreate it since I removed the /tmp files... they still exist in /tmp/bounce but with the old game.js). Let me create a fresh dbg in /tmp with the current game.js and the bot from dev-test.cjs.

Let me write a small script that extracts the bot from dev-test.cjs... simpler: recreate dbg.cjs in /tmp/bounce with the updated game.js and the bot.cjs (which is the same bot logic).

bot.cjs in /tmp/bounce has the same candidate set ✓ (dir/delay/post/chain with commitVar) ✓.

Let me copy the current game.js to /tmp/bounce and run dbg.cjs 3.

The bot is stuck in a loop around the pad at 51-52 / bridge at 56-59: it launches from the pad, lands around 59.5 (vx=0 → stuck on the bridge?), dies, respawns at 49, repeats.

At 179.0: x=59.50 y=13.07 vx=0 → y=13.07 means it's low (near the ground at row 14) → it fell past the bridge into the spikes region? Actually y=13.07 with vx=0 — it's falling.

Hmm, the pad launch now lands further? The pad is at 51-52 unchanged. The bridge is at 56-59 unchanged. So why is it failing now? The difference is the widened crossing at 36-41 — but that's earlier in the level. Score=800 means it collected 800 points (4 hoops + ... hmm 800 = 4 hoops + 2 checkpoints? = 400+400 = 800 ✓ or 6 hoops... whatever).

Actually the bot reached the pad section, so it passed the crossing. It's now looping at the pad→bridge jump and dying 95 times.

Wait, earlier (before widening) the bot cleared L4 with 0 deaths. The pad/bridge part is unchanged... unless the crumbling blocks at 36-41 are now in a 'gone' state when the bot reaches the bridge? No, they're separate.

Hmm, but the bridge blocks at 56-59 collapse 0.5 s after contact and take 3 s to return. If the bot lands on the bridge, the blocks collapse behind it; if it fails to reach the solid block at 60-63, it falls. Now with 95 deaths it's looping.

Why would it fail now but not before? Because the bot arrives at the pad with a different state (e.g., different crumble timers, or a different plan cache). Or because the bot's approach to the pad changed.

Look at the trace: at 183-199 the bot oscillates: at 49.5-51 (ground before the pad) accelerating, then at 54-57 airborne at y≈7.5-8.8 (pad launch), then at 59.5 vx=0 y=13 (fell). So it's landing at ~59.5 which is the last X block (59) — and vx=0?! vx=0 means it hit a wall. The solid block at 60-63 has top y=9; the ball arriving at x=59.5 with y≈8.5 would collide with the block's left face at x=60 → pushed to 59.5 ✓ then falls onto the bridge/ground.

Hmm, so the ball is arriving slightly too high/too fast and hitting the wall at col 60 instead of landing on the bridge.

Earlier (before the widening) the trace showed: 15.0 x=59.54 y=8.63 vx=6.00 → 16.0 x=59.70 y=8.60 vx=0 → 17.0 x=60.32 y=8.27 vx=4.01 → 18.0 x=61.47 y=8.28 vx=0.47 → 19.0 x=65.20 y=7.84 vx=6.00 → success. So it hit the wall at 60 but then climbed onto the block (it was at y=8.27, above the block top y=9? center 8.27 → bottom 8.77 < 9 → above the block top ✓ so it could move right onto it ✓).

Now it's arriving at y≈8.4-8.8 (bottom 8.9-9.3) → marginal, sometimes below the block top → blocked → falls back onto the bridge → the bridge has collapsed → falls into spikes → death.

The difference must be the takeoff point on the pad. Before, the bot approached the pad at full speed and took off at col 51 (center 51.5) → landed at 57.74 on the bridge. Now it seems to take off later (from col 52, center 52.5) → lands at 58.74 → and then hits the wall at 60.

Hmm, actually the trace shows it airborne at x=54-57 with y≈7.5-8.0 (apex ~7.5) then at 59.5 y=13 — so it descended past the bridge level. If the bridge blocks are already 'gone' (collapsed from previous attempts), the ball falls through! That's it: after many deaths, the bridge blocks are in various states; the bot lands where the blocks are gone → falls → dies.

But the blocks return after 3 s. The bot keeps re-attempting every ~2 s, hitting blocks that are mid-cycle.

Anyway, the deeper issue: the bot's route is marginal. Let me reconsider the design of this final stretch to be more forgiving while still hard.

Ideas:
1. Move the pad further left so the takeoff is earlier and the landing is more central on the bridge.
2. Make the bridge longer (5-6 blocks) so the landing window is wider.
3. Lower the bridge to row 10 (4 tiles above ground) instead of row 9 (5 tiles) — then the pad launch (6 tiles) has more margin, and the landing is at a lower height... but the solid block at 60-63 must match the bridge height.

Let me redesign: bridge at row 10 (top surface y=10, 4 tiles above ground), solid block cols 60-63 rows 10-14 (top y=10). Pad at 51-52.

Pad launch from takeoff at 51.5 (speed 6): rise needed to land on surface y=10 = 4 tiles. h=4 at t1=0.312, t2=1.162. x(t2) = 51.5+6.97 = 58.47 → col 58 ✓ on the bridge (56-59) ✓. Takeoff at 52.5 → 59.47 → col 59 ✓ still on the bridge ✓ (last block, then must move onto 60 ✓).

Clearing the bridge's left face (x=56, y∈[10,11)): at x=55.5 the ball must have bottom < 10 → rise > 4 → t>0.312 → x = 51.5+1.87 = 53.37 at t=0.312; at x=55.5 (t=0.667) rise = 10.84-4.89 = 5.95 → bottom = 14-5.95 = 8.05 < 10 ✓ clears easily ✓.

Also the ball could land on the bridge earlier: it's above y=10 from x=53.37 to 58.47; the bridge starts at x=56 → it lands when descending to bottom=10 at x=58.47 ✓ mid-bridge ✓ good margin.

With takeoff at 52.5: above y=10 from 54.37 to 59.47 → lands at 59.47 → col 59 (last block) → then it must immediately step onto the solid block at col 60 (same height ✓ continuous) ✓ fine.

Hmm, but if the takeoff is at 52.5 and the landing at 59.47, the block at 59 starts collapsing → the ball must move right onto 60 ✓ it's adjacent ✓.

Also, what if the ball takes off from the ground before the pad? It can't reach y=10 with a normal bounce (needs 4 > 3) ✓ pad required ✓.

And the solid block at 60-63 top y=10: the ball on it occupies row 9 → hoop at (61,9).

Then X at 64-65 row 10, spikes at row 14 cols 64-65, ground 66-71.

Drop from y=10 at col 65 to the ground: 4 tiles ✓.

Hoop at (61,9) — need to update the map.

Also the crystal shelf at cols 31-35 rows 7,8 and the plateau at 22-28 rows 9-14 (top y=9). Hmm, the plateau is at top y=9 (5 tiles) reached from the pad at 16-17 ✓ verified earlier ✓ keep.

Let me also double check the plateau route still works: takeoff at 16.5 speed 6 → lands at 22.74 ✓ on the plateau (22-28) ✓.

Now let me also reconsider the L4 first crossing (36-41, 6 blocks at row 14 over spikes at row 15). The bot died there? Let me check the earlier trace... it reached the pad section, so it crossed ✓.

Let me now also reconsider whether the bot's failure at the bridge was due to collapsed blocks. With the new height (row 10), the landing is at col 58 (mid-bridge) ✓ more margin ✓.

Let me apply the change:
- L4 row 9: currently `......................#######...........................XXXX####XX......` → cols 22-28 plateau, X 56-59, #### 60-63, XX 64-65. With the bridge lowered to row 10, row 9 should have only the plateau (22-28) and the solid block 60-63 (rows 10-14 → row 9 empty). So row 9 becomes: cols 22-28 '#######' only.
- Row 10: currently `......................#######...............................####........` → plateau 22-28, #### 60-63. New: plateau 22-28, X 56-59, #### 60-63, XX 64-65.
- Rows 11,12,13: plateau 22-28, #### 60-63 (unchanged).
- Row 14: X at 56-59 → now spikes at 56-59 (already '^' in row 14: `...PP^^^^^^^####^^######` → 53-59 '^', 60-63 '#', 64-65 '^', 66-71 '#') ✓ unchanged ✓.
- Hoop: (61,8) → (61,9).
- Row 8: currently `.........................O.....#####.........................O..........` → O at 25, ##### 31-35 (shelf), O at 61. The hoop at 61 must move to row 9. So row 8: O at 25, shelf 31-35, no O at 61.
- Row 9: add O at 61.

Let me write out the new L4 rows:

Row 6: `.................................*......................................` (crystal at 33) ✓ unchanged.
Row 7: `...............................#####....................................` shelf 31-35 ✓ unchanged.
Row 8: `.........................O.....#####..................................` → O at 25, shelf 31-35. Length 72: 25 dots + 'O' + 5 dots (26-30) + '#####' (31-35) + 36 dots (36-71) = 25+1+5+5+36 = 72 ✓
Row 9: `......................#######....................O.XXXX.............` hmm need O at 61 and X at 56-59.
Let me construct: cols 0-21 dots (22), 22-28 '#######' (7), 29-55 dots (27), 56-59 'XXXX' (4), 60 dots? No — the hoop at 61 is at row 9, and the solid block 60-63 occupies rows 10-14, so at row 9 col 60 is empty, col 61 = 'O', cols 62-71 empty.
So row 9: 22 dots + 7 '#' + 27 dots (29-55) + 'XXXX' (56-59) + '.' (60) + 'O' (61) + 10 dots (62-71) = 22+7+27+4+1+1+10 = 72 ✓
Row 10: 22 dots + '#######' (22-28) + 27 dots (29-55) + 'XXXX' (56-59) + '####' (60-63) + 'XX' (64-65) + 6 dots (66-71) = 22+7+27+4+4+2+6 = 72 ✓
Row 11: 22 dots + '#######' + 31 dots (29-59) + '####' (60-63) + 8 dots = 22+7+31+4+8 = 72 ✓
Row 12: same as 11 but with 'D' at 70: `......................#######...............................####......D.` → 22 dots + 7 + 31 dots + 4 + 6 dots (64-69) + 'D' (70) + '.' (71) = 22+7+31+4+6+1+1 = 72 ✓ (matches the existing row 12) ✓
Row 13: `..S..O................#######.C..O.........O.....C..........####....O.E.` ✓ unchanged (has #### at 60-63) ✓
Row 14: unchanged ✓
Row 15: unchanged ✓

Wait, row 11 currently is `......................#######...............................####........` = 22+7+31+4+8 = 72 ✓ keep.

Row 12 currently `......................#######...............................####......D.` ✓ keep.

So changes: rows 8, 9, 10.

Let me generate these strings precisely with node.

Also, the hoop at (61,9): the ball on the block top (surface y=10) has center 9.5 → row 9 ✓ ✓.

Let me also double check the crystal shelf (31-35, rows 7,8) reachability from the plateau (top y=9, center 8.5): rise 2 → land on shelf top y=7 ✓ unchanged ✓.

Let me generate and apply.

Wait, r9: 22 dots + 7 '#' = 29 chars (cols 0-28), then 27 dots → cols 29-55, then 'XXXX' → 56-59, then '.' → 60, 'O' → 61, then 10 dots → 62-71 ✓ total 72 ✓.

Hmm but the printed r9 shows `......................#######...........................XXXX.O..........` — count the dots between '#######' and 'XXXX': should be 27. Let me trust the length check (72) and the construction ✓.

r10: 22 dots + 7 + 27 dots + 4 + 4 + 2 + 6 = 72 ✓.

Now replace L4's rows 8, 9, 10 in game.js.

Current L4 rows:
row 8: '.........................O.....#####.........................O..........'
row 9: '......................#######...........................XXXX####XX......'
row 10: '......................#######...............................####........'

New:
row 8: '.........................O.....#####....................................'
row 9: '......................#######...........................XXXX.O..........'
row 10: '......................#######...........................XXXX####XX......'

So row 10 takes the old row 9 content shifted down by one (bridge at row 10), and row 9 gets the bridge... wait no. Old row 9 had the bridge at row 9. New row 9 should NOT have the bridge (it's at row 10 now). But my generated r9 has 'XXXX' at 56-59! That's wrong.

Let me redo: the bridge is now at row 10. So:
- row 9: plateau 22-28 only + hoop 'O' at 61.
- row 10: plateau 22-28 + X 56-59 + #### 60-63 + XX 64-65.

r9 should be: 22 dots + '#######' (22-28) + dots (29-60) + 'O' (61) + dots (62-71) = 22+7+32+1+10 = 72 ✓

Let me regenerate.

Now the hoop at (61,9) is directly above the solid block at 60-63 (rows 10-14) ✓ supported ✓ (validateLevel requires support below: grid[10][61] = '#' ✓ since row 10 has '####' at 60-63 ✓).

Let me apply the edit.

Wait — the old row 9 in the file was `'......................#######...........................XXXX####XX......'` and old row 10 was `'......................#######...............................####........'`. My edit's oldText used the row-9 string with `...........................XXXX####XX` (27 dots) — it matched ✓ good.

Now the new rows: row 8 (no O at 61), row 9 (O at 61), row 10 (bridge + block).

Hmm, but I need to double check the plateau: rows 9-14 at cols 22-28. New row 9 has '#######' at 22-28 ✓, row 10 has it ✓, rows 11-14 ✓. So the plateau spans rows 9-14 ✓ top surface y=9 ✓ unchanged ✓.

And the bridge X at row 10 cols 56-59 → top surface y=10 ✓.
Solid block cols 60-63 rows 10-14 ✓ top y=10 ✓.
X at 64-65 row 10 ✓ top y=10 ✓.
Spikes at row 14 cols 56-59 and 64-65 ✓ (from the row-14 string: 53-59 '^', 60-63 '#', 64-65 '^') ✓.

Hoop at (61,9) ✓.

Now let me re-run the dbg for L4.

L4 completes with 0 deaths ✓ (19.6 s). L3 completes with 1 death (22 s) — acceptable (the bot is imperfect), and the earlier full test showed L3 with 1 death and still clearing.

Let me re-run the full test suite.

All checks pass. Let me also re-run the render harness (level data changed).

Then final review of the files.

One remaining concern: the L3 bot has 1 death. Let me see where — probably the crumbling crossing. That's fine; a human with the checkpoint banked has 3 lives.

Let me also double check the L3 map visually now (with the widened crossing) and L4.

Let me print the maps.

Also, I want to double-check the "level 4 is the hardest" claim and the pacing. L4 has: spikes early, pad→high plateau, crumble crossing (6 blocks), spikes, pad→high crumbling bridge, crumbling bridge 2, exit. Yes, hardest ✓.

Let me print the final maps for a visual sanity check.

The maps look good. A few observations:

L1: the exit door 'D'/'E' at col 53, spikes at 47-48 → 5 clear tiles before the door ✓. Hoop at 44, spikes at 47-48 ✓.

Hmm, L1 row 13: `..S...O....O..C......O...####.....O......C..O........E..` — index 53 = 'E' ✓, 54-55 dots ✓.

L1 checkpoint 2 at 41 ✓ before the spikes at 47-48 ✓.

L2: checkpoint 1 at 20 (right after the pad at 22-23? no, the pad is at 22-23 and the checkpoint at 20 is before it) ✓ banks progress before the pad+plateau challenge ✓. Checkpoint 2 at 36 ✓ before the spikes at 41-42 and the pad+spike field ✓.

Hmm, wait: the checkpoint at 20 is 2 tiles before the pad at 22. If the player dies on the plateau route they respawn at 20 → 2 tiles of run-up before the pad. Reaching max speed takes ~1 tile ✓ OK.

L3: checkpoint 1 at 28 (right before the 6-block crossing at 30-35) ✓; checkpoint 2 at 44 (before the step+raised bridge at 46-50) ✓.

L4: checkpoint 1 at 30 (before the 6-block crumble crossing at 36-41) ✓; checkpoint 2 at 49 (before the pad→high crumbling bridge) ✓.

L4 hoop at 61 (row 9) sits on the solid block ✓.

One thing to verify in L4: the drop from the plateau (cols 22-28, top y=9) at col 29 down to the ground. The checkpoint at 30 ✓ safe landing ✓.

Another: L4's crystal shelf at cols 31-35 rows 7,8 — the player drops from the plateau and might bonk the shelf underside; I verified earlier that at speed 6 there's no clipping ✓ and at lower speeds the ball lands before reaching the shelf ✓.

Hmm, let me double check at speed 3: the ball leaves the plateau at center 28.5 falling. It falls 5 tiles (from center 8.5 to 13.5) in 0.674 s → at speed 3 it travels 2.02 tiles → lands at 30.52 ✓ before the shelf (31) ✓. At speed 4: 2.7 → 31.2 → at the moment it reaches x=31.0 (t=0.625), it has fallen 11*0.39 = 4.29 → center 12.79 → spans [12.29,13.29] → shelf y-range [7,9) → no overlap ✓ safe. At speed 5: x=31 at t=0.5 → fallen 2.75 → center 11.25 → spans [10.75,11.75] → no overlap ✓. At speed 6: computed ✓. Good.

Now, one more consideration: the L4 crystal route requires bouncing off the plateau's right edge onto the shelf. Verified ✓ (the bot found it in an earlier run? The crystal test for L4 said "gameover t=83.9" but crystal taken ✓ — actually it says PASS for "crystal in level 4 is reachable" ✓).

Now let me do a final read of index.html and style.css, and make sure the HUD/CSS matches the new lives rendering (only `life on` spans now; the `.life` base style without `.on` is unused but harmless).

Let me also consider adding a subtle detail: the spec says the ball must be "immediately distinguishable from every other object in all four" ✓ red circle with dark outline; pads are lime; spikes near-white; hoops gold; checkpoints cyan/dim-blue; crystal violet; door gray/white. ✓

One risk: in L3 (EMBER) the block color is purple #5b3fa8 and the crystal is #c58bff — distinct from red ✓.

Let me do a final full read of game.js top section (constants + levels) to confirm nothing is off, then finish.

Actually, one more important check: the `#hud` shows `HOOPS n` — the number of hoops remaining ✓.

Also: should the HUD show lives as ball icons — `.life` is 12px round red ✓.

Let me also confirm there's no leftover reference to `run.shake`.

Let me grep.

Also check for `performance.now()` usage ✓ fine in browsers.

Let me grep for potential issues.

Clean. No leftover shake/TODO/console.log in game.js.

Let me do a final read of index.html and style.css to confirm they're complete and consistent, and add a small note: the `.life` non-on style is now unused but harmless.

One last consideration: the spec says "The camera viewport is 16×16 tiles — 128×128 logical pixels — scaled up crisply to suit a desktop browser." 512×512 ✓.

Also "Keep a single HUD bar fixed below the 128×128 world viewport" ✓.

Let me verify index.html once more and confirm the overlay is inside #screen (so cards overlay the world) ✓.

One more: the title screen renders a flat background from LEVELS[0].pal.bg (#0d2018, dark green) — fine.

Let me read index.html and style.css back.

Also, I should double check that the game handles the case where the player presses Space during 'dying' — advance() does nothing for 'dying' ✓ and Space also sets keys.bounce ✓ harmless.

And during 'gameover', Space does nothing ✓.

Final: let me view index.html.

Good. One improvement: the HUD's `#level` and `#hoops` labels — the spec says "the current level number, the number of hoops remaining". "LEVEL 1" and "HOOPS 6" are fine labels (not objective text).

Hmm, "Do not add objective text" — "HOOPS 6" is a count, not an objective ✓.

Let me finalize. One last thing: I'd like to make sure the game is playable on a laptop where 512px + 44px HUD fits ✓.

Let me also add `user-select:none` and `touch-action:none`? Not needed.

One more potential issue: `body { min-height:100vh; display:flex; align-items:center; justify-content:center; }` — if the window is shorter than 564px the content could overflow; body min-height 100vh with flex centering could clip the top. Let me add `padding: 16px 0` and `overflow:auto`. Minor robustness. Let me add.

Also prevent text selection flicker.

Let me make a small CSS tweak.

Then finish with a summary.

Final verification: run both harnesses one more time to be sure nothing broke, and confirm no background processes.

Let me run both.

Everything passes, no background processes. Let me do a final read of the whole game.js once to be safe about completeness (I've read most of it; let me read the first 175 lines to confirm the constants/levels section is intact).

Actually I already read the level maps via the dump ✓ and the constants section earlier ✓. Let me do a quick read of lines 1-40 to confirm.

Then write the summary.

Everything is in place. Note: `H_PAD` is used for the pad launch height — but the pad height is defined as 6.0 ✓.

Wait, one thing: `H_PAD` is declared but the pad launch uses `V_PAD` ✓.

Done. Let me write the summary.

Files:
- index.html (entry point)
- style.css
- game.js
- dev-test.cjs, dev-render.cjs (dev harnesses, not loaded by the page)

Let me summarize the implementation and the verification results.