Having different behavior for the +- states makes sense for dual purpose! Lack of feedback makes it feel empty (understandable with it being a game-jam game) and the design for levels 3-5 work, but feel a little too open. There's too much room for error that shouldn't be possible yet. If there were a few more levels before the 5th one (couldn't figure it out) that would help me understand how to work around the moving object, then it would be better. But still, clever idea and level design!