Thanks for making this and letting me play it! I'm having some trouble with level three on the browser build - when I pick up the cube, something happens and the room changes, but I seem to die almost straight afterwards.
From what I saw up to then, it's a cool idea! If you plan to keep working on it, I think that adding a visual indicator of the goal, and explaining the puzzle angle (where you deliberately can't move the platform backwards), would be good places to improve next.