The music is pretty good and I like the little guy bobbing along with it! The end state isn't very final, you can still move around (and jump into lava and die and restart the level" even after the YOU WIN message is displayed.
I also discovered another perhaps unintended feature: pressing mine on the same note multiple times works. Like you would normally have to hit 8 beats, once each, rigt? But you can just as well hit four beats twice each, and mine twice as fast. If intended, cool secret! But if not, maybe a bug, haha