I hope that they release Crysis 2 WARHEAD -- Like the same game, but from another angle...
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and then u get to play Nomad or Psycho! that would be great! Or a prequel where you play Prophet from the time he goes back to the Island -- until he finds Alcatraz and his buddies after the sub attack... [what all happens in between]
Maybe a mix of both - the prequel starts about 12 hours before the main-game and. ends with their evac during the defense of the Central Station. Maybe it also clears up the fate of Nomad, Prophet and Psycho after C1 which you can play BOTH, either as Nomad or Psycho but always with both together, allowing also 2-player-coop (Coop-campaign ftw!)
Edit: Or screw prequel-part and let it play totally elsewhere. We saw a worldmap during the outro and where the Ceph got bases all over the world. Why not go to Sydney, London, Rio or Moscow?