The Ultimate Doom is a standalone expansion pack for Doom developed by id Software. Apart from the base game, it includes a completely new episode that continues the story of the game. ###Plot The game's plot seems loosely connected to the base game as id Software was busy with developing Quake. The simply players set out on a journey to kill off four guardians of hell. This episode serves as a prequel to Doom 2. ###Gameplay Minor additions were made to Doom's engine, as it now featured severa...