Nice entry! The mechanics were very solid, and I especially liked that the placement of boxes was restricted to the map grid, thus making solutions/placement easy and consistent. I really liked how there were little ways to minimize the amount of crates used also. If you did restart a level however, it didn't subtract the crates placed from your score even if it removed them from the map. Penalty for restarting I suppose? Also, I did start getting confused as the levels went on, in that it was hard to tell what was solid and what wasn't. Still, the mechanics and gameplay were solid. Well done!