The idea has potential, but currently a loop of all Cs seems to win every time. If you build on what you have with some additional mechanics that force the player to strategise a bit more it could be a nice little game. Good job on the art and audio.

This is a super cool concept! Although currently there's little point in engaging with it, since a scale made entirely of basic hits does the job just fine. Maybe each note can only be used a certain number of times, so you have to power up your notes so you don't waste them. Please keep working on this though, it's awesome!

The music is awesome, but it's too easy.

I think it could be more difficult. For example, letting player predict the boss's actions in advance to respond accordingly. It might also help to add damage and effect indicators, as it's not very intuitive to know boss's actions just from the height of the notes.

The Ultimate text still active when I win the game.