I played through the entire campaign with my wife and it was one of the best cooperative experiences in my gaming career. (videochums.com)
While the campaign mode only features a 2 Player cooperative experience, you are still able to do the terrorist hunt missions with up to 4 players online. (co-optimus.com)
It also provides an amazing cooperative experience for people that also works fine for single player. (articles.gamerheadquarters.com)