Call of Duty: World at War is a classic Call of Duty game from back in 2008, it ran on the Call of Duty 4: Modern Warfare engine. The game is well known for introducing a zombies mode that almost got cancelled, but turned out to be a very popular mode for the Call of Duty community. Please do not let the reputation of current Call of Duty games get in the way of this, this is nothing like those ones. The campaign is short, but it's good and there's even co op if you wanna play with a buddy. Now that we have the basic information out of the way, discuss away!
Waw campaign was my second favorite, first being the Modern Warfare series (this was futuristic BEFORE they went TOO OVERBOARD with the futuristic stuff) I've never played zombies because I don't like games that have no end, like that. But World At War's campaign, brutal, and can be a bit scary for the younger players (depended on how much you mind actual warfare) but very great of a game.