We guess zombies are now passé with Call of Duty as their latest title, Call of Duty: Ghosts does away with zombies and instead put in aliens in their 4-player coop mode... " Call of Duty: Ghosts introduces Extinction - an all-new 1-4 player cooperative game mode featuring a unique blend of fast-paced survival action, FPS base defense, scavenging and class leveling. Pre-order now.