Goomba-stomping Cthulu is certainly fun! Although I think I'm missing something... the shopwizard is always at the bottom of the tower, and you can only hold one jetpack at a time, and the jetpack runs out of charge, and it looks like you're supposed to go up... so I'm not really sure how to make any progress? The "tutorial" section really could be expanded.
(Update): OK, read the comments and found out you can bounce on the ghosts. I also discovered you can walljump, which I'm not sure is intentional... anyways, was pretty fun. Although, as others have mentioned, the "without dying" part is a bit of a cheat since you still lose your progress.