Coin Hop: a game starter your AI assistant can add sounds to

A tiny HTML5 platformer (no build step, no dependencies) with real sound effects, set up so Claude Code, Codex or Cursor can find and add more sounds by themselves through the free SFXMint MCP server.

• Jump, coin, stomp, win and game-over sounds already wired, with mute (M) and the first-input audio unlock browsers need.
• Every sound is CC0: use it in a game you sell, no credit needed. Files, sources and hashes are in SOUNDS.md.
• AGENTS.md tells your assistant where sounds go and how to add one, so a one-line request is enough.

Run it

npx serve .

or python3 -m http.server, then open the address it prints. (Opening index.html straight from disk blocks the scripts and the audio.)

Arrows or A/D move, Space jumps, R restarts, M mutes. On a phone: tap the left or right third to move, the middle to jump.

Connect your AI assistant

The MCP server is https://sfxmint.com/mcp (the configs here add ?ref=starter, which only tells SFXMint the connection came from this starter). No account or key for the library.

• Claude Code: open the folder and run claude; it reads .mcp.json and asks once to enable sfxmint.
• Cursor: open the folder; .cursor/mcp.json is picked up (enable it under Settings → MCP if asked).
• Codex: run codex mcp add sfxmint --url "https://sfxmint.com/mcp?ref=starter" once, then codex in this folder.

Things to ask it

• "Add a landing sound when the player lands on a platform." (The game has none yet: try this first.)
• "Add a dash on Shift with a short whoosh."
• "Make each coin in a row sound a little higher."
• "Add a quiet looping cave ambience behind the game."
• "Turn this into a horror game: swap every sound for a creepier one."

It searches the library, downloads the file into assets/sfx/, wires it in src/sfx.js and src/game.js, and lists it in SOUNDS.md. When the library has nothing close, it says so and gives you a link to make that exact sound in SFXMint's AI Studio (free to make and hear).

Files

index.html        the page
src/game.js       the game: movement, platforms, coins, slimes
src/sfx.js        sound effects: loading, unlock, play, mute
assets/sfx/       the sound files (CC0)
SOUNDS.md         where each sound came from, with its SHA-256
AGENTS.md         instructions for AI assistants (CLAUDE.md points to it)
.mcp.json         the SFXMint MCP server for Claude Code (.cursor/mcp.json for Cursor)

License

CC0 1.0: code, sounds and text. The sounds are AI-generated; if you ship on Steam or itch.io, disclose AI-generated audio (guide).