This is a really nice map and deserves something between 4/5 and 5/5. The map design is really nice and creative. The only reason why I do not think that this deserves a 5/5 is because of the boxes standing on top of each other are not interlocked. (Sry, I have the feeling that this is not proper English, but I think you understand me...)
I understand what you mean. I just don't think that interlocking the boxes would be that necessary, besides, it is meant for gameplay.