Having played 20 games in this jam, I think this is the coolest use of the theme so far! Moving the walls to solve puzzles is smart and creative, and gave a couple cool scenarios. My favorite was the one where I moved the shelf with the wall, but it often ended up over the hole, so I needed to nudge it a bit, being careful not to make the room dark!
Graphics were simple, but cool. You could push the coolness factor even further, by adding some shader, to make the graphics "pop" more. Then again- the game looks good as it it :)
Sound was good, but a bit of background music would be even better (you can check out https://mobygratis.com/ to get music for your future projects).
As I said- this was the best use of the theme I've seen in this jam so far! Finding the boxes was fun and the game length was perfect for a jam game (maybe a bit longer would be cool. Like two more difficult boxes). I could see this as a "big" release with different rooms that have various rules.
Keep up the great work!