I love rhythm games! I see a lot of potential. your game is very fun.
But as someone who loves these kind of games, I have some feedback:
1- the first stage is pretty much the best, but it isnt perfect. the big skull obscures what you need to see exactly when you need to see it more. Also there is almost no feedback to when you hit the notes.
It is well made otherwise, almost got a perfect score once!
2- the drums! I cant get it. something is off. I always get the bad ending.