Really impressive game, probably my favorite so far! The puzzles, especially 8 to 15, are actually very clever and not immediately obvious, which I think is pretty crazy for a jam game (and the main reason I made a non-puzzle platformer lol). The art of course is also great, and the game looks quite polished overall.
A minor detail, I accidentally glitched myself or a box into the ground a few times in levels 4 and 15 when expanding it close to me or to another box. Then again, thanks for unlocking all levels up front, would have been a shame to get stuck.