The Ultimate Doom

The Ultimate Doom was included in Doom 3 Collector's Edition for the Xbox, which was released in 2005. This port includes an exclusive level, "Sewers". It featured multiplayer like the PC version, however not through Xbox Live. This port was programmed by Vicarious Visions. The Xbox version of Doom 3: Resurrection of Evil also contains this port. This particular "port" actually appears to be an emulation of the aged DOS version of the game; furthermore, it seems to have been somewhat rushed, as it is somewhat limited in functionality, and has a few bugs and design quirks.