"The powers-that-be are extremely insistent that DOOM 3 on Xbox is not a port. Their aversion to this moniker isn't for the obvious reason. In fact, it's because the game features more modes along with tweaks to existing elements of the PC game. Strange but true, loyal reader. For one, the Xbox version will feature co-op via Xbox Live. That's a feature even the beloved Halo 2 omitted from its finished product. Because of the differences two human players cause to the story elements and cutscenes, new dialogue was recorded and missions were altered to make more sense. Compare this to many other co-op games, where NPCs say the same thing whether they're supposed to be talking to one or two heroes."