Nice take on the boss rush theme, seems like an original idea for a platformer boss rush thing. I like the fact that music is quite in rhythm with the game. It's sometimes quite difficult to understand what is happening however. You don't have much time to realize the attack and it happened to me that when I understand what I need to do it's already too late. Maybe the kind of "get good" thing was the intention but it made the experience worse for me.
Still a nice game, well done!