I like the idea of a platforming puzzle game where you have to push crates around, and I can see some potential in the concept from the puzzles at the start.
I found most of the following puzzles could be circumvented just by jumping over everything and pushing the boxes on their side, though; perhaps this could be fixed by carefully considering how high the player can jump and disallowing box rotation? It would also be nice if the pushable boxes were a different colour to the walls, too.
That said, this game is a fun little playground, and it's nice for the amount of time you were allowed to spend on it.