Great game! I had a lot of fun playing it. The art is amazing and the sounds are great! The gameplay is the best part though. You really did a good job with this game!
One small thing: It would be good to still somehow see the health of the player when entering the level up screen, because I sometimes got the option to receive 20hp, but my old brain just couldn't remember how much I had left. Also I don't see my health in a number, but in a shape, so writing "gain +20 hp" doesn't tell me that much, because I don't know how much health I actually have (except when I get a maximum health increase).
But except for this small detail I had a lot of fun! Keep it up!