This is my favourite game from the Jam so far! Seeing that thumbnail made me think "No way that works seamlessly." and you proved me fully wrong. I think you have implemented and presented the mechanic really well, it was fun to playthrough each puzzle with the staircase/white button one being the most difficult.
The only thing I found awkward was the dragging of the boxes with the mouse in some cases, not exactly correlating to mouse position but I can imagine that being down to the time limit perhaps. In 48 hours this is an amazing production!!!