I admittedly haven't played the game myself yet, but IGN is one of the outlets that has gone live with its 6/10 , which reveals that the campaign's always-online nature means it can't be paused, and if you're idle for what the game deems to be too long it'll boot you out. For a mode that is traditionally offline and totally separate from the online portion of the game, this might come as a shock to some players.
DarkSwarm is a top-down tactical shooter featuring synthetically engineered elite mercenaries battling an alien infection across procedurally generated maps, emphasizing co-op gameplay.