Treyarch says it is working hard on a fix and already released an update aimed at the reported issues two days ago. "People buy this game mainly for multiplayer features. The main feature being unplayable makes this nothing but an overpriced paperweight," said gamer "Ian" on the BBC's Newsbeat Facebook page.
Treyarch has acknowledged in a post on its forums that many gamers are experiencing connectivity and other issues with the popular title.
"We've already updated the game with one 'hot fix' since Tuesday's release that has improved many of those connectivity problems, and we've got more coming, so stay tuned. We're committed to doing everything we can to support the best online experience, and we're working quickly to resolve this issue."
Within 24 hours of going on sale, the title sold more than 7 million copies, 5.6 million in the U.S. and 1.4 million in the U.K.