Played through it 4-player co-op the whole way through. Much of the game's fun comes from the emergent gameplay, which the co-op does wonders to facilitate. The campaign's writing is unfortunately all over the place, mostly forgettable and occasionally Definitely Not Good. There are a lot of problematic elements for people smarter & more motivated than me to pick apart, but I can at least safely say that a race war did not enhance the game's narrative.