Okay so, I got really stuck on level 5 (didn't play further yet). I thought the game was bugged when I sometimes could reach the button by jumping and sometimes not, and then the box falling down, and I got softlocked there after getting crushed by the closing door too after trying to jump through.
After like 5 min of running around, I had the box drop up, which I thought that it was a bug that it didn't do that before. But quickly after that I understood the puzzle, and I think it's really great. But! The game is missing an introduction to the box gravity mechanic. Like, a level where that is the only thing, and is required. Because level 5 had more than that and as such it's not obvious to experiment with the box as it looks basically the same no matter which way its gravity is when held. One could use their brain to figure out the box acts like it does though, except that games work with game logic so it's not as obvious, even though it is obvious after realizing it in this case.
Edit: Played the rest of the game now, and honestly, the puzzles where really good. They weren't overwhelming at all, and seemed simple but took brainpower to solve, so really good!