I wish there was a difficulty curve. It goes from easy to meh to 'Wow, this is pretty freaking hard' on level 27, and then back to meh, and just downright sadistic on the final level. Other than that, great game.
SPOILER DO NOT READ IF YOU HAVE NOT BEATEN THE GAME. I'M WARNING YOU, DO NOT READ IF YOU WANT TO BEAT THE GAME? --- What happens if you get the cake? Being the Genre Savvy kind of guy I am, portaled around it, and I'm too lazy to do level 40 again.