It's surprisingly sturdy. I have brought the same game to multiple conventions without the box breaking.
I already played this wonderful game a few times, and I am working on alternative ways to play, because my game group is loving this game. New rules, new game modes, and different ways to set up the boxes. I am debating to order a second game for variety and a higher player count. (On a side note: if you are interested in some of my ideas I could shoot you a P.M.)
But I've noticed already, that penguin's beak will punch little holes into the ground. I don't know if there is a satisfying solution for this problem, but the beak seems to be very sharp and it's standing out quite a lot.