I really like this game, but:
I would like to see a score after each run.
I tried to play with a gamepad and in the first bossroom, while i was fighting, a door opened after I had touched it, I don't know if it is a bug and if it is related with the pad, it has happened only once.
The green notes make you faster, but there isn't anything that makes you tougher (I haven't tried all the items yet).