Todd: That's a good question. The Xbox version, because it's in contemporaneous development with the PC. When it was started, basically was conceived as a console implementation of what we're trying to do on the PC, as opposed to a port where they take whatever we do on the PC and "boom" slap it on the Xbox. The Xbox version was designed from the ground up to support co-operative play over System Link and Xbox Live. There [were] some changes, concessions, considerations that had to be made from a lot of different standpoints in terms of stuff as mundane as how narrow the hallways are to the ability of the AI of the enemies to focus on one versus two players -- because it's no fun to play the co-op guy that the world seems to ignore -- to how the narrative of single-player story is told.

On the PC version, it was always conceived of as a purely single-player experience. The whole, "you're alone in your room and all the lights are turned out." It's an experience where we want you to be afraid to get up and turn the lights off because you're alone. Whereas, because the console market is different, because people like to play together. Now, we won't have the ability to do split-screen, but the console consumer is more, "Hey, we love co-op" and it's all supported within the Xbox with Xbox Live and System Link. It made a lot more sense for us when we were designing [the game] to include that feature, [which] was never considered to be a critical feature for the PC [version], given that our goal from the start with the PC version was to make it the best single-player game that id had ever made.