There are 4-5 'Special Ops' mini-campaigns on the game which you can play either solo, or with a single friend (maximum 2 players). They don't interfere with the main campaign from what I have seen, but they add a new dimension to the game that the previous one didn't have.
Really enjoying this game so far, they've really stepped it up a notch.
Really enjoying this game so far, they've really stepped it up a notch.