name	browser-platformer-weak-llm
description	Build a very small 2D browser jump-and-run or platformer in HTML, CSS, and JavaScript using staged prompts optimized for weak models. Use when OpenCode needs to create or extend a simple browser platformer, keep the game runnable after every step, or verify gameplay changes with lightweight debug hooks and Node-runnable self-checks.

Browser Platformer Weak LLM

Keep scope narrow. Use plain index.html, styles.css, and script.js, one canvas, rectangle-based entities, no framework, no build step, and no external assets.

Workflow

Open references/staged-prompts.md.
Pick the next unfinished stage and send that stage prompt with minimal edits.
Preserve all working behavior from earlier stages. Do not refactor aggressively once a stage passes.
Keep verification hooks alive from stage 1 onward.
If a stage fails, fix that stage before moving forward.

Required Architecture

Keep gameplay logic in script.js.
Use one shared state object and arrays of plain objects for platforms, hazards, goals, and coins.
Use rectangle collisions and simple deterministic update steps.
Make the game core runnable in Node without DOM access.
Export createGameState, stepGame, and runSelfCheck through module.exports when available.
Expose window.__platformerTest in the browser with at least getSnapshot(), setKey(code, pressed), step(frames), reset(), and runSelfCheck().
Return JSON-serializable objects from verification helpers.

Verification Discipline

After each stage, re-read the edited files and confirm the requested pieces exist.
Run node --check script.js when Node is available.
Run the exported self-check in Node when available:

node -e "const g=require('./script.js'); const result=g.runSelfCheck(); console.log(JSON.stringify(result, null, 2)); process.exit(result.passed ? 0 : 1)"

If browser automation is available, also check window.__platformerTest. If it is not available, say so explicitly instead of claiming full runtime browser verification.
Keep the self-check current. Do not leave stale assertions from an earlier stage only.

References

Use references/staged-prompts.md for the copy-paste stage prompts.
Keep the verification block from each prompt intact so the agent actually proves the stage works.

Browser Platformer Weak LLM

Keep scope narrow. Use plain index.html, styles.css, and script.js, one canvas, rectangle-based entities, no framework, no build step, and no external assets.

Workflow

Open references/staged-prompts.md.

Pick the next unfinished stage and send that stage prompt with minimal edits.

Preserve all working behavior from earlier stages. Do not refactor aggressively once a stage passes.

Keep verification hooks alive from stage 1 onward.

If a stage fails, fix that stage before moving forward.

Required Architecture

Keep gameplay logic in script.js.

Use one shared state object and arrays of plain objects for platforms, hazards, goals, and coins.

Use rectangle collisions and simple deterministic update steps.

Make the game core runnable in Node without DOM access.

Export createGameState, stepGame, and runSelfCheck through module.exports when available.

Expose window.__platformerTest in the browser with at least getSnapshot(), setKey(code, pressed), step(frames), reset(), and runSelfCheck().

Return JSON-serializable objects from verification helpers.

Verification Discipline

After each stage, re-read the edited files and confirm the requested pieces exist.

Run node --check script.js when Node is available.

Run the exported self-check in Node when available:

node -e "const g=require('./script.js'); const result=g.runSelfCheck(); console.log(JSON.stringify(result, null, 2)); process.exit(result.passed ? 0 : 1)"

If browser automation is available, also check window.__platformerTest. If it is not available, say so explicitly instead of claiming full runtime browser verification.

Keep the self-check current. Do not leave stale assertions from an earlier stage only.

References

Use references/staged-prompts.md for the copy-paste stage prompts.

Keep the verification block from each prompt intact so the agent actually proves the stage works.

browser-platformer-weak-llm