Thanks for your comment!
No, you're very much right - I ran out of time for designing puzzles due to trying to figure out how to make Godot do what I wanted it to do (I've been trying to migrate away from Unity, and this is my first published Godot game). Had there been more time, I definitely would've added more levels to make the puzzle element more apparent, as I do believe that's what would make the game far more compelling.
Movement is something that I could spend a long time refining, and definitely the movement of the boxes is something that I do wish to work on.