the online story co-op was pretty fun. 4-8 players play the story thats seperate from the main single player, you get xp for kills and completing mission objectives and then you use collect gray tech to upgrade your defense and weapons, I could definitely see myself wasting a lot of time getting to the last level like with COD4.
I haven't had a chance to play the competitive stuff but I imagine its more of the same.
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"Moris should be here soon to rub it in my face..." -Pizza