I understand that developers try to break from the mold once in awhile but the absance of a campain delves a bit too much from the rest.  Even a simple campain will give the player a feel of progress in the game, if nothing else.  If I knew that this game had no campain, I most likley wouldn't have picked it up.  Don't get me wrong, the game is fun, I just feel that I won't put nearly as much time in this game for my gaming dollars as I would have otherwise.