This is really cool! I think the concept and the execution of this is really really well done. Just three things that I noticed: some sound effects are noticably louder than other (the rmb shot), and that the bullets should be way bigger, the black bullets were almost invisible for me, and lastly the movement smoothing has to go, or at least it has to be reduced dramatically, since it bullet hells really need small precise movements, and player character in this game feels like he's sliding on ice.
Still, wonderful nice job! I really enjoyed it