This game was super fun :D
It's a very cool concept and it is done well. The addition of the spike balls and the no music zones were added at good points, as I settled into a static solution of right before they were introduced, even though climbing with the note blocks was definitely far a consistent pattern.
Sometimes waiting for the music player to come back around if you missed the note by one tile was annoying, but it wasn't that big of an issue due to how short the levels and game was overall, some sort of reward for completing the levels as fast as possible or with as few music meter used up as possible would be a great addition imo, as it would hopefully reward players that play in a more risky and fast passed way, and would give more replay value.
Excellent game, good luck in the jam :)