The 12 year old kids hoarding the sentry turrets really are an ass pain, still I managed to complete all Tribute waves on recruit. The last couple of waves were the best since me and another good teamplayer had enough money to basically have fun with it. We were roaming the map with two smartguns for a finish, killing left, right and centre while the other two squad members were duking it out elsewhere (I think either in operations or that longish bridging hallway which stretches between two buildings). Either way, most fun I've had in a game for a long time, Bar the ridiculous alien heads, t'was a good representation of the movie.