I really liked this game! It has a lot of potential and I hope you continue to work on it after the jam. Just a few things to improve on: The door and win area are the same color and I thought I could go through the red part of the door; maybe change the door and key color to a different color), also, the suddenly popping in and out walls in level 4 were kind of annoying since they were hard to predict.
Also, not really a critique of your game but a feature I thought you could add was some areas where the player isn't allowed to bring the orange box so he/she would have to be extra careful in leading the character.