This is excellent. I've never seen a physics game done with a vacuum mechanic before, but you implemented it very well. Boxes can be a little bit of a pain to move around, the physics work quite well, and the Rube Goldberg style of the levels is fun. I enjoyed watching everything fall into place as the buttons were hit. The light-hearted carnival motif is sweet and relaxing, and the creatures are cute. Sound effects are good.
The only issues I see are that the music can be repetitive and the game was fairly easy. Easy isn't necessarily bad, but I never felt challenged. On the other hand, you left me wanting more.