"Some websites say complete the campaign but it is already unlocked under co-op when you first play it. I am playing it now and i havent beat the campaign."@en . . "Do you have to unlock nazi zombies in Call of Duty World at War"@en . . . "Some websites say complete the campaign but it is already unlocked under co-op when you first play it. I am playing it now and i havent beat the campaign."@en .