Well, as the first entry in the music game jam that I had the pleasure of reviewing, let me just say, great work!
I think you could add a bit more to this overall, I don't necessarily think that you need to kill the player for interacting with the walls, maybe just have them bounce off since it feels a little high stakes and sometimes pretty hard to control yourself. More feedback for correct answers would be nice. I think a red or green change on the buttons could make it pretty clear, but right now there's a delay and it's hard to tell the right answer. I think you could also add a win screen when you win or maybe something neat at the ending. The music also ends pretty abruptly when you get the right answer. A nice fadeout is pretty easy to achieve so maybe think about that in the future!
Overall, great work!