1UP writes: "One aspect of the game that I didn't get to try out was the co-op, a big part of what makes these sorts of games so much fun. Dead Nation is supposed to support both offline and online co-op (Housemarque doesn't seem entirely confident that online co-op will be ready at launch, but I'm betting it'll have to be). The one level that I played felt like it was still pretty early -- it had all pieces in place, from the enemies to the environments, but it lacked the proper difficulty and emotional curves you'd expect. Left 4 Dead is good because of its pacing; its highs and lows that help keep you on edge. According to Housemarque, little of that is in their game yet -- which isn't surprising since they also say Dead Nation won't be out until well into 2010.
Still, what I played demonstrated that the fundamentals are in place for this game to be a ton of fun. Dead Nation was definitely one of the pleasant surprises of the show".