What is it with zombies and videogames? Valve is getting ready to launch Left 4 Dead, a game which is supposed to convey the experience through which a zombie apocalypse survivor will go through while battling his way to safety. Blizzard has recently introduced zombies in World of Warcraft, as a pre-launch event which will go on until the launch of the Wrath of the Lich King expansion. Even Rockstar has succumbed to the lure of the undead, unveiling an infection which is raging in the multiplayer modes of Grand Theft Auto IV.

Now Treyarch is giving in to the dark side by saying that a secret unlockable mode will be included in Call of Duty: World at War. The mode will be co operative and will offer as many as four players a chance to fight zombies in something that looks like a cross between left 4 Dead and Counter Strike. The mode will only be available to those intrepid players who manage to complete the single player campaign of the video game. The announcement, made on an interview with GameTrailers TV, might come as a bit of a surprise to people who have been watching the development of the game, which is being promoted as an action survival title that wants to offer the player the experience of an American soldier hopping on an island in the Pacific theater of World War II.

It seems that the enemies will be Nazi soldiers reanimated by a mysterious force. They will be coming at the players in waves and they will not stop until all the protagonists are dead, much like in the Horde mode of Gears of War 2. Footage from the game shows players using in game currency to get weapons and defensive structures in order to hold back the zombies. Well, it will be fun to see them around again since the launch of Wolfenstein.