I built Polyvale, a free browser tower defense where every tower is an instrument, with Claude Opus 5.5 in Claude Code

I built Polyvale, a rhythm tower defense game, using Claude (Opus 5.5) in Claude Code. The trailer was also made by Claude. Free to play in your browser. No install, no ads: [https://polyvale.foxbase.dev](https://polyvale.foxbase.dev) What the game is * Each tower is an instrument. It only attacks on its own notes in a 16-step loop, so your defense is also the song. * Upgrades change what the tower plays: some branches play more notes, others fewer and heavier. * Enemies hop on the beat. * A mix meter rewards a balanced band. Staying in the "groove" zone gives +20% damage and charges a Drop that doubles damage. If the band gets too loud or one instrument dominates, you lose the bonus. * 10 towers and 6 maps. **Each map has its own music genre**. * It also has a skill tree with branching choices, map twists like lily pads, burrows and ice, and a boss. How Claude was used * Claude wrote all of the code: about 6,700 lines of JavaScript using Canvas 2D and Web Audio. There are no…