I love the simplicity of this entry - presentation as well I feel was one of its strongest points. Good design as well as I figured out almost instantly that you can grow pumpkins with Boo on top to reach higher places (Oh, and the increased pumpkin detail is such a nice touch too). I also really appreciated that restart had to be held down instead of instant.
Gameplay wise, it would be nice if there were a couple of in-between checkpoints especially since the player moves at a relatively slower pace. It would also be great if hazards were made a lot more prominent (or simply more dangerous looking, I didn't the vine-spike thingies at the start would hurt me lol).
Great entry, good luck for the rest of the jam!