A:Answer It can play offline. I've played it without an active internet connection. However the game seemed to have issues with the endgame statistics and xp reporting when I did so. This was around launch though, so that may not be the case any longer. The game specifically has an offline campaign mode. I'm not sure what the other reviewer is talking about.
Also, this is a great game at its price point. This is why it is selling out at a lot of retailers. It isnt a AAA title, but it swings like one. I've had a ton of fun with it, alone and with pals.
Hope any of this is actually helpful.