lol the mario jump sound.
Pretty cool concept. Adds a lot of depth to puzzle solving. Perhaps if no checkpoint system, just save the position of objects around a puzzle/hurdle. Forcing a player to redo a puzzle is just tedious, will make players have negative thoughts about the game. (This is of course ignoring time constraint and just a comment about the game if in the future).
Does the camera purposefully lag behind? I don't like not being able to see where I'm going, unless the goal is to slow the player down/make them cautious. Also your collision rects seem a bit off for some objects? Interesting that objects die if they hit spikes, not sure how I feel about that. I tried to put a block over a spike so I didn't hit it lol.
Cool game. I think you could definitely work on this post jam, pump out some nice little assets and polish and it'll be a quality platformer.
Edit: also it would be cool if the different objects you control, control differently. Would make it feel like you're really controlling different things and make the game feel less same-y