i loved the whole "writing on the wall" aesthetic and the soundtrack reminded me of cruelty squads, and it went super hard. the player controller is a bit clunky for a platformer so that's something i'd change, along with giving everything sound effects would be good.
(tip for godot physics, this might be what you're looking for but it also might not so disregard at will)
with the box when you pick it up it acts weird because it's colliding with all the walls and as it cannot change its position (the code is setting the position) it only changes its rotation. to change this you'll want to make the colliders not active or work on another layer. you probably could just have it set the boxes collision mask to 0 or something while it's picked up (box.collision_mask = 0). or you could even do something like box.get_child(0).disabled = true while it's picked up, assuming that the first child of the rigidbody is the collision shape. hope this helps the janky physics if you were looking to solve it