The game kind of breaks when you get drops from a couple of waves. The fire rate becomes so large that all rooms after that will be trivial. Also, way too many hearts are dropped, ensuring you are basically topped up at all points of the game.
In many cases, enemies spawned on top of me with no warning. The only way to prevent this was to stand near the edge of the room.
Art was cool though. Sad I was not able to full screen the game to actually see it properly. Overall, a cool entry with some spots to improve on.