At first this was really difficult but after I figured out the hollow night pogo mechanic, it turned into a pretty fun little arcade game. Couple suggestion if you're looking for some feedback:
1) I think making the players attack a bit bigger (larger hitbox) because it was was pretty difficult to swing at the enemies with such a tight margin of error.
2) Also think making the players hitbox a bit smaller because sometimes I would die and it didn't feel like I really ran into an enemy
Other than that, this was a pretty fun arcade game albeit really challenging.