The bosses and enemies are all weird aliens with shit designs. Even though I kinda like the personalities of them, they're still really forgettable. On top there being no actual levels you go through other than what stage you fight the boss. The overworld starts with a more expanded Santa Destroy, and all the other overworlds you access feel less and less for there to explore. You get this feeling that areas that are marked out in no access red would unlock eventually, and nope. You're expecting the large space ship in the center to be something and it's just a hallway to the final boss.