Hehe, I'm bad at this game, but I like it nontheless.
I did notice some "ghost damage" (playing while there's no note deals damage, and letting a note hit you deals damage, so missing a note deals double damage). Personally, I'd let the player spam the keys, maybe just breaking the combo (Guitar Hero and OSU! do this fine). It was pretty fun to slowly learn the music, although switching focus from top to bottom of the screen is still difficult for me...
Music is lit, fam. Love how it gets more difficult, as if the wizard is pulling a "last stand" riff. Ii know this is a jam game, but I'd love to see this concept polished and expanded (I may even explore this myself).
(I got 93% while writing this!!!)