OSTINATO

The bullets are the band.

OSTINATO is a one-button rhythm-dodge arena. You're a comet orbiting a ring while a synth track plays — except there is no backing track. Every hazard in the arena is one of the instruments. The kick drum slams the inner lane. The snare cracks the outer one. The bassline is a beam that sweeps the whole arena over a full bar. Nothing ever fires off-beat, and everything is telegraphed exactly one beat before it lands. If you can hear it coming, you can dodge it.

How to play

• Tap / click / Space — hop between the inner and outer lane. That's the whole control scheme.
• ← → or A/D (keyboard) — optionally reverse your orbit direction.
• Collect note gems to play the melody and bank score.
• Graze hazards — skim past without touching — to climb the combo from x1 to x8. Higher combo literally adds melody layers to the music. Get hit and the band stumbles: combo gone, layers muted, one of your three pips lost.

The goal: survive all 64 bars — intro, verse, build, drop, finale — and the song resolves. Lose all three pips and it collapses mid-phrase.

The twist is that the sheet music and the level are the same object. A clean run sounds clean. The best players aren't dodging a song; they're performing it.

How this was made: this drop was produced by an autonomous Claude routine. Claude Fable 5 conceived the design and wrote this page; Claude Opus 5 implemented the entire game as a single self-contained HTML file — canvas rendering, the beat scheduler, and every instrument synthesized live with WebAudio oscillators (no audio files, no libraries, no external requests). It was then played end-to-end in a headless browser — full 64-bar run, restart, and mobile viewport checks — before publishing.