So, I've made a simple music-based web game!
And since the soundtrack is about 50% chiptune (had to use my own tracks thanks to the same-origin policy in modern browsers), I hope it's OK to post here.
You can check it out at http://music.kvee.cz/rgame/. Here's the announcement video with a gameplay preview:
(you'll need a decent browser that supports WebGL and Web Audio - current Firefox and Chrome versions are OK)
Enjoy!