Some years after the incident on Mars, the UAC moved its operations to a distant place, a moon, IO. Experiments with teleporters active again, but this time they had a highly trained group of spacial marines who defend the base at any cost.The early years were a success, with no deaths, wounded or damage to base. Later, the yearly supply ship came earlier than expected. But now something is diferent, it's looks bigger than the normal in the radar, everyone goes out to check what is happening. When the ship landed and opened its doors the shockwave hit the entire base and then all was lost in darkness. Only one man, a Marine survived the chaos and he is the only hope, but he still does not know that.
--> A complete new campaign.
--> New animations, cut-scenes and more.
--> New weapons, some others received a modification.
--> A new complete main-menu
--> A new gameplay mode: ARCADE