The style looks simple, which is what I like. For such a short tutorial I managed to understand the mechanics pretty quickly so that's a plus too. I guess there are multiple choices on which rectangle to pick but there isn't a difference, so maybe there should be only 2 rectangle randomly somewhere and you have to drag the objects towards it before they hit the walls. That's just an idea, I'm not saying you have to change it but overall it seems interesting to play.