It turns out, co-operative play isn’t just an option – playing with up to three friends, or with others online, will be the core campaign experience. During a reveal event in April, developer Treyarch announced that the campaign would be a four-player co-op mode with large, open environments – it even promised a more complex story in which multiple playthroughs may be required to get the full picture.īut how does this play out in practice? Recently, we got to play a demo of the Campaign mode – here’s what we discovered.