After Rocksteady Studios released Batman: Arkham Asylum, gamers have been waiting to take up the “dark knight’s” mantle once again in the upcoming sequel, Batman: Arkham City. Rumors that the sequel will include cooperative gameplay have also helped feed the hype.
However, Rocksteady Studios squashed the rumor in an Interview with IGN Entertainment last week.

The multiplayer rumors first gained shape after a video of Batman and Joker fighting back to back against a swarm of thugs appeared on the web. In a gaming climate where multiplayer capability can make or break a game, Rocksteady shot down the rumor and stuck to their single-player game roots.
“So it might not be the fashionable choice, it might not get us an extra tick on the box, but we are convinced, and we hope that gamers will agree when they get to play the finished game, that we have made the right decision,” Hill said.
Fake Batman: Arkham City Co-op Gameplay