Fun puzzle game, the need to use different boxes is a very cool idea, and the puzzles are well made as well.
I would have liked the controls for the direction to lift/drop a box be a bit easier, as I have lost few times due to mistakes in this. For example, you may make the direction change with arrow keys, or the mouse, or make the player press down the E key first then set the direction, then the box is dropped/lifted on key up. That's just my opinion.