The music is beautiful! Very intuitive, no instructions needed to figure out how to play which is appreciated. It seems quite hard to actually get through a room taking no damage, especially since the enemies are right on top of you as soon as you enter.
I'd have liked to see some variation in the room layouts, it always seems to be up and it's the same grouping every time.
My only major suggestion would be please add text skip. I can read 10x faster than it appears on screen. I would have not got to playing if the intro went on any longer!