Super cool and simple! This one had me there for a while, eventually I got a highscore of 8 by lucking out with a bunch of single boxes
speaking of lucking out.. my one complain is that it feels a little too luck based!
I think this game would benefit SO much from another tetris mechanic: being able to see the upcoming piece and being able to hold it for later. Being able to strategize and plan a little more would allow for crazier box stacks.
Simple and very cute concept, great entry :)