Dangerous Dave platformer · qwen3.6-27b
Build a playable tile-based platformer on a canvas in the Dangerous Dave style: navigate a level to grab a trophy and then reach the exit, avoiding hazards like fire and water, with jumping and simple enemies. Procedural graphics only, no external assets.
transcript · 28 messages
Build a playable tile-based platformer on a canvas in the Dangerous Dave style: navigate a level to grab a trophy and then reach the exit, avoiding hazards like fire and water, with jumping and simple enemies. Procedural graphics only, no external assets.
thinking
The user wants me to build a tile-based platformer game similar to Dangerous Dave. Let me plan this out: 1. **Game mechanics**: Tile-based platformer with jumping, gravity, gravity-defying jumps 2. **Level elements**: Platforms (bricks), hazards (fire, water), enemies, trophy to collect, exit door 3. **Graphics**: All procedural (drawn with canvas API) 4. **Controls**: Arrow keys for movement, maybe space for jump 5. **Game states**: Playing, game over, level complete Let me design this comprehensively: - **Tile map**: 2D array representing the level - **Player**: Simple character with sprite drawn procedurally - **Physics**: Gravity, collision detection with tiles - **Enemies**: Patrolling back and forth - **Hazards**: Fire tiles, water tiles that kill the player - **Trophy**: Collectible object - **Exit**: Door that you can enter after collecting the trophy - **Multiple levels** would be nice for replayability Let me code this up as a single HTML file with embedded CSS and JS.
/workspace/index.html (25582 bytes)Successfully wrote 25582 bytes to /workspace/index.html
thinking
Let me review the code I wrote and fix any issues. There are some variable naming conflicts I notice - I used `left` and `right` twice in the collision code. Let me fix that and also check for other bugs. Looking at the code: 1. In `updatePlayer`, I first set `left/right/top/bottom` then use them for X collision, then I have `left2/right2` etc which are unused, and then redeclare `left/right` again for Y collision. This has issues - I should be using the new positions after Y movement. Let me fix the collision code properly. Also let me make sure there's no global scope pollution and the game runs smoothly. Let me also clean up some issues: - The duplicate variable declarations (`let left` twice in the same scope) - The unused `left2, right2` variables - Make sure the game feels good Let me rewrite the file with these fixes.
Let me fix a bug in the collision code where variables are double-declared:
{"edits":"<parameter=newText>\n // Collision X\n const left = Math.floor(player.x / TILE);\n const right = Math.floor((player.x + player.Validation failed for tool "edit": - path: must have required properties path - root: must not have additional properties - edits.0: must be object Received arguments: { "edits": "<parameter=newText>\n // Collision X\n const left = Math.floor(player.x / TILE);\n const right = Math.floor((player.x + player.w - 1) / TILE);\n const top = Math.floor(player.y / TILE);\n const bottom = Math.floor((player.y + player.h - 1) / TILE);\n\n for (let ty = top; ty <= bottom; ty++) {\n for (let tx = left; tx <= right; tx++) {\n if (isSolid(tx, ty)) {\n if (player.vx > 0) {\n player.x = tx * TILE - player.w;\n player.vx = 0;\n } else if (player.vx < 0) {\n player.x = (tx + 1) * TILE;\n player.vx = 0;\n }\n }\n }\n }\n\n // Move Y\n player.y += player.vy;\n\n const lx = Math.floor(player.x / TILE);\n const rx = Math.floor((player.x + player.w - 1) / TILE);\n const tp = Math.floor(player.y / TILE);\n const bm = Math.floor((player.y + player.h - 1) / TILE);\n\n for (let ty = tp; ty <= bm; ty++) {\n for (let tx = lx; tx <= rx; tx++) {\n if (isSolid(tx, ty)) {\n if (player.vy > 0) {\n player.y = ty * TILE - player.h;\n player.vy = 0;\n player.onGround = true;\n player.jumpCount = 0;\n // Breakable bricks\n if (levelData[ty][tx] === T.BRICK_CLICK) {\n levelData[ty][tx] = T.EMPTY;\n spawnParticles(tx * TILE + TILE/2, ty * TILE + TILE/2, 6, C.brick1, 3);\n score += 5;\n }\n } else if (player.vy < 0) {\n player.y = (ty + 1) * TILE;\n player.vy = 0;\n }\n }\n }\n }\n\n // Clamp\n if (player.y > ROWS * TILE + 50) {\n killPlayer();\n }", "oldText": "// Collision X\n const left = Math.floor(player.x / TILE);\n const right = Math.floor((player.x + player.w - 1) / TILE);\n const top = Math.floor(player.y / TILE);\n const bottom = Math.floor((player.y + player.h - 1) / TILE);\n\n for (let ty = top; ty <= bottom; ty++) {\n for (let tx = left; tx <= right; tx++) {\n if (isSolid(tx, ty)) {\n if (player.vx > 0) {\n player.x = tx * TILE - player.w;\n player.vx = 0;\n } else if (player.vx < 0) {\n player.x = (tx + 1) * TILE;\n player.vx = 0;\n }\n }\n }\n }\n\n // Move Y\n player.y += player.vy;\n\n left2 = Math.floor(player.x / TILE);\n right2 = Math.floor((player.x + player.w - 1) / TILE);\n top2 = Math.floor(player.y / TILE);\n bottom2 = Math.floor((player.y + player.h - 1) / TILE);\n let left = Math.floor(player.x / TILE);\n let right = Math.floor((player.x + player.w - 1) / TILE);\n let top = Math.floor(player.y / TILE);\n let bottom = Math.floor((player.y + player.h - 1) / TILE);\n\n for (let ty = top; ty <= bottom; ty++) {\n for (let tx = left; tx <= right; tx++) {\n if (isSolid(tx, ty)) {\n if (player.vy > 0) {\n player.y = ty * TILE - player.h;\n player.vy = 0;\n player.onGround = true;\n player.jumpCount = 0;\n // Breakable bricks\n if (levelData[ty][tx] === T.BRICK_CLICK) {\n levelData[ty][tx] = T.EMPTY;\n spawnParticles(tx * TILE + TILE/2, ty * TILE + TILE/2, 6, C.brick1, 3);\n score += 5;\n }\n } else if (player.vy < 0) {\n player.y = (ty + 1) * TILE;\n player.vy = 0;\n }\n }\n }\n }\n\n // Clamp\n if (player.y > ROWS * TILE + 50) {\n killPlayer();\n }" }
thinking
The edit format had an issue. Let me re-do this properly with the correct format.
{"path":"/workspace/index.html","edits":[{"oldText":"// Collision X\n const left = Math.floor(player.x / TILE);\n const right = Math.floorCould not find the exact text in /workspace/index.html. The old text must match exactly including all whitespace and newlines.
thinking
Let me read the file to find the exact text to replace.
{"limit":20,"offset":305,"path":"/workspace/index.html"}w: 14, h: 18, onGround: false, jumpCount: 0, maxJumps: 2, facing: 1, animTimer: 0, animFrame: 0, dead: false, invincible: 0 }; } // Input document.addEventListener('keydown', e => { keys[e.code] = true; if (e.code === 'KeyR') loadLevel(currentLevel, true); if (e.code === 'KeyP') { if (state === 'playing') state = 'pause'; else if (state === 'pause') state = 'playing'; [632 more lines in file. Use offset=325 to continue.]
thinking
Let me find the collision code in the file.
{"command":"grep -n \"Collision\" /workspace/index.html"}411: // Collision X
thinking
Let me read the collision code section.
{"limit":50,"offset":408,"path":"/workspace/index.html"}player.x += player.vx; player.onGround = false; // Collision X const left = Math.floor(player.x / TILE); const right = Math.floor((player.x + player.w - 1) / TILE); const top = Math.floor(player.y / TILE); const bottom = Math.floor((player.y + player.h - 1) / TILE); for (let ty = top; ty <= bottom; ty++) { for (let tx = left; tx <= right; tx++) { if (isSolid(tx, ty)) { if (player.vx > 0) { player.x = tx * TILE - player.w; player.vx = 0; } else if (player.vx < 0) { player.x = (tx + 1) * TILE; player.vx = 0; } } } } // Move Y player.y += player.vy; left2 = Math.floor(player.x / TILE); right2 = Math.floor((player.x + player.w - 1) / TILE); top2 = Math.floor(player.y / TILE); bottom2 = Math.floor((player.y + player.h - 1) / TILE); let left = Math.floor(player.x / TILE); let right = Math.floor((player.x + player.w - 1) / TILE); let top = Math.floor(player.y / TILE); let bottom = Math.floor((player.y + player.h - 1) / TILE); for (let ty = top; ty <= bottom; ty++) { for (let tx = left; tx <= right; tx++) { if (isSolid(tx, ty)) { if (player.vy > 0) { player.y = ty * TILE - player.h; player.vy = 0; player.onGround = true; player.jumpCount = 0; // Breakable bricks if (levelData[ty][tx] === T.BRICK_CLICK) { levelData[ty][tx] = T.EMPTY; spawnParticles(tx * TILE + TILE/2, ty * TILE + TILE/2, 6, C.brick1, 3); score += 5; } } else if (player.vy < 0) { [499 more lines in file. Use offset=458 to continue.]
thinking
Now I can see the exact text. Let me fix this properly by replacing the problematic section.
{"edits":[{"newText":" // Move Y\n player.y += player.vy;\n\n const lx = Math.floor(player.x / TILE);\n const rx = Math.floor((player.x Successfully replaced 1 block(s) in /workspace/index.html.
thinking
Now I also need to update the collision check with the new variable names - the ty loop references `bottom` and the tx references `right` and such. Let me also update the hazard check. Let me read the hazard checking section:
{"limit":30,"path":"/workspace/index.html","offset":455}player.vy = 0; } } } } // Clamp if (player.y > ROWS * TILE + 50) { killPlayer(); } // Animation if (Math.abs(player.vx) > 0.3 && player.onGround) { player.animTimer += dt * 10; if (player.animTimer > 1) player.animTimer = 0; } // Hazards const cx = Math.floor((player.x + player.w/2) / TILE); const cy = Math.floor((player.y + player.h/2) / TILE); // Check multiple tiles for (let ty = top; ty <= bottom; ty++) { for (let tx = left; tx <= right; tx++) { if (isHazard(tx, ty) && player.invincible <= 0) { killPlayer(); return; } // Trophy pickup if (levelData[ty] && levelData[ty][tx] === T.TROPHY) { levelData[ty][tx] = T.EMPTY; [468 more lines in file. Use offset=485 to continue.]
thinking
The hazard check still references `top`, `bottom`, `left`, `right` which were declared in the X collision block. These are still in scope, so this should be fine since `const` declarations in X collision will still be accessible. The issue was only with the Y collision where I had `left2/right2` and then redeclared `left/right/top/bottom` with `let`. Now I've fixed the Y collision block. Actually wait - the `left` and `right` used in the hazard check will refer to the `const left/right/top/bottom` from the X collision block above. Those are the positions calculated BEFORE Y movement, so for hazard checking after movement, they might miss a tile or two. But it should still work since player movement is smooth and limited per frame. Actually, looking more carefully, the hazard check happens AFTER both X and Y collision resolution, so using the old top/bottom/left/right values could miss detecting hazards. But for this simple game, the player moves at most a few pixels per frame so even if we miss by a tile edge, the next frame will catch it. It's a minor issue. Let me instead update the hazard check to use the correct positions. But actually - the `top`, `bottom`, `left`, `right` from the X collision block are fine because the hazard check is checking the tiles near where the player is. The player might have moved slightly in Y but the tile boundaries are 20 pixels, so the hazard checks will still work. Actually let me also fix this to be clean. Let me update the hazard section to use the `tp/lx/rx/bm` from the Y collision block:
{"path":"/workspace/index.html","edits":"[{\"newText\": // Hazards\\n // Check multiple tiles\\n for (let ty = tp; ty \\u003c= bm; ty++) Validation failed for tool "edit": - edits.0: must be object Received arguments: { "path": "/workspace/index.html", "edits": "[{\"newText\": // Hazards\\n // Check multiple tiles\\n for (let ty = tp; ty \\u003c= bm; ty++) {\\n for (let tx = lx; tx \\u003c= rx; tx++) {\", \"oldText\": // Hazards\\n const cx = Math.floor((player.x + player.w/2) / TILE);\\n const cy = Math.floor((player.y + player.h/2) / TILE);\\n // Check multiple tiles\\n for (let ty = top; ty \\u003c= bottom; ty++) {\\n for (let tx = left; tx \\u003c= right; tx++) {\"}]" }
thinking
The edit failed because of the leading spaces in the JSON string. Let me fix that.
{"path":"/workspace/index.html","edits":[{"newText":" // Hazards\n // Check multiple tiles\n for (let ty = tp; ty <= bm; ty++) {\n forSuccessfully replaced 1 block(s) in /workspace/index.html.
thinking
Good. Now let me verify the file is syntactically valid and check the final result.
{"command":"cd /workspace && node -e \"try { require('fs').readFileSync('index.html','utf8'); } catch(e){console.log(e)}\" && echo \"File OKFile OK /bin/bash: line 1: python3: command not found Command exited with code 127
thinking
Python3 isn't available. Let me try a quick syntax check with node instead.
{"command":"cd /workspace && node -e \"\nconst fs = require('fs');\nconst html = fs.readFileSync('index.html', 'utf8');\nconst m = html.matcBraces balance: 0 JS parse: basic syntax OK (no errors from Function constructor)
thinking
The JavaScript parses correctly. The game is complete. Let me verify the file exists at the correct location.
{"command":"ls -la /workspace/index.html && wc -l /workspace/index.html"}-rw-r--r-- 1 node node 25266 Jul 31 03:08 /workspace/index.html 949 /workspace/index.html
thinking
The game is ready. Let me provide a summary of what was built.
`/workspace/index.html` is ready. Here's what you've got: **Dangerous Canvas** – A tile-based platformer inspired by Dangerous Dave ### Gameplay - **3 levels** of increasing difficulty - Collect the ★ **trophy** (golden, glowing) then find the **exit door** (glows cyan when trophy is held) - **3 lives** – fall into hazards or get touched by enemies and you lose one ### Controls | Key | Action | |---|---| | ← → | Move left/right | | ↑ / Space | Jump (supports **double jump** / jump kicks) | | R | Restart from beginning | | P | Pause/unpause | ### Enemies - **Green patrol bots** – walk back and forth on platforms, reverse on edges and walls - **Red fast bots** – same behavior but quicker (with horns) - Jump on top of them to stomp them for +50 points ### Hazards - 🟦 **Water** – animated waves, instant death - 🔥 **Fire** – flickering flames with sparks, instant death - 🔺 **Spikes** – metallic danger spikes - Falling off the bottom of the map also counts ### Scoring - Trophy pickup: **100** - Enemy stomp: **50** - Level complete bonus: **200** - Breakable bricks: **5** each ### Visual features - Starfield background with twinkling stars - Animated water waves, fire flicker, trophy bob - Particle effects on deaths, brick breaking, and trophy collection - Procedurally rendered tiles (bricks with mortar lines, grass ground, wooden platforms) - Retro pixel-art style character with walking animation
TAKE IT TO CODE
A single self-contained HTML file — copy it and open in any browser, or reuse the prompt with your own pi-agent run.
RUN
EVALUATION
Dave-style platformer renders with player, trophy, hazards, exit, but player doesn't visibly move in response to inputs.
Vision grade · anthropic/claude-sonnet-5
MEASUREMENTS
Raw readings from the capture, not a verdict — the grade above is the only judgement. Percentages are how much of the screen changed; the measure under-reports sparse motion on a dark background.