Great game ! I played it with a controller and everything was smooth. It really feels polished with the nice intro and outro. Maybe adding a little bit more SFX could make the game even more polished.
My only complaint is box placement : it is quite hard to stack two box on top of each other : they always want to fall instead of fitting neatly on top of each others. maybe adding a little bit of magnetism or increasing box friction could help.
A great entry, good job !