Demo: https://rhythm-seodang-web.vercel.app/
The problem I wanted to solve: most rhythm game workflows are heavy. Proprietary editors, manual charting, fixed gameplay patterns, desktop-only. I wanted something where you could just... open a browser tab and start messing around.
How it works:
- Music comes from AI services (Suno/Udio). No user uploads, no copyright headaches.
- Essentia.js (WASM port) runs entirely in-browser. Beat tracking, onset detection, energy curves, segment boundaries, all client-side.
- The output is a timing-only chart. What you do with that timing is up to you.
The fun part is the minigame sandbox. Charts and gameplay are completely decoupled. You define spawn rules, input handling, rendering, all in short JS functions. Same chart can become a taiko-style drum game, a directional swipe thing, or something experimental. Preview runs instantly.
Tech: Next.js, Essentia.js, custom rhythm engine, Canvas rendering, deployed on Vercel.
Current state: playable with sample tracks, chart generation works, minigame workshop is functional. In-platform AI music generation (prompt to track to playable) is next. Still rough around the edges.
If you've worked with WebAudio or rhythm engine internals, curious what you think. Feedback welcome.