Cool game, loved the concept! The art is pretty nice.
My only complain maybe would be that despite this being a puzzle game, the puzzles felt a little easy to me, and what was a little harder and tedious was to fight the physics engine to get the box where I want it to be. In a puzzle game, you often want the other way around: you want it to be challenging to find the solution, and easy to actually achieve it once you have the correct idea in mind.
But that kind of stuff is hard to get right in a game jam, so no worries, and good job!