I built this game from scratch in c++. Most of the sounds you hear are synthesized at runtime by an audio synthesizer I also wrote. I generate sound this way because (1) it's cool and (2) it makes for fast iteration on game design.

I arrived at this game design over years of noodling around with tiny prototypes. I love rhythm games but I sometimes find them so restrictive - i.e., usually the song is already set in stone and you're graded by how closely your button presses match the song's rhythms. So with this prototype I'm trying to break out of the restrictions typical of rhythm games by letting players just play the music themselves, with no musical training necessary.