While playing I noticed some issues. First the player jitters when moving make sure to use the LateUpdate or FixedUpdate function to set the cameras position to the players position and second the colliders of the boxes make it feel uncontrollable because I suppose they are not a rectangle which makes it hard to place the boxes precisly. But I think the idea with the hidden Key "E" in the level is a nice touch and is pretty creative and the puzzles were ok. Well done considering this your first game jam!