Perhaps the best known Alien-themed total conversion for DOOM was also the first of its kind for any video game. Aliens TC, created by Justin Fisher, proved not only popular but also incredibly influential, paving the way for countless similar total conversion mods since. Originally created for the original DOOM, updated versions were also released for The Ultimate DOOM and DOOM II (the latter created by Jason Mezzacca rather than Fisher). The mod is noted for its suspenseful atmosphere, in contrast to the famously fast-paced gameplay of the DOOM games.
Being a total conversion, the mod alters many aspects of the game to bring them more in line with the Alien franchise. This includes new levels based on the plot of Aliens, new textures, new sound effects actually extracted from the film and placed in the game, new weapons such as the Pulse Rifle, Smartgun and Power Loader, and new enemies based on the Xenomorph and its life cycle. The player character was also changed to become an unidentified Colonial Marine.
Aliens TC would be followed by several sequels, none of which were created by Fisher. These include Aliens DOOM, which featured an original story involving the Colonial Marines investigating a Weyland-Yutani facility where the employees have gone rogue with the Xenomorphs they have bred, Aliens DOOM 3 - Aliens versus Predator, Aliens: The Second Nukage and AliensX. A partial conversion mod, known as the Aliens versus Predator Theme Patch, incorporated numerous Aliens-themed textures, sounds, weapons and enemies into the original game without otherwise altering its levels.
Aliens: Colonial Marines by Oriol Comerma/Deimos Anomaly for GZDoom is the most recent Aliens total conversion created for DOOM. Released in 2011, it is the most advanced Aliens project to date, powered for GZDoom with many modern effects such as 3D floors and dynamic lights. It takes its weapons and music from the Alien Trilogy video game and utilizes textures from Aliens versus Predator 2, along with new, highly detailed Xenomorph sprites. The game is set on LV-426, where the player adopts the role of Corporal Hicks. The mod is essentially an adaptation (or reinterpretation) of the film Aliens but in the vein of a classic first-person shooter. The mod also has a bonus level in which the players are hunted by Predators and must fight their way to safety.
Duke Nukem 3D
Compared to DOOM, many of the Alien-themed total conversions created for Duke Nukem 3D never progressed past the development stage, with unfinished demos being the only available versions. Alien Extermination (also known as Alienz), and Aliens are the only total conversions for the game that were ever completed. Slawomir "Law" Lawrynowicz is best known for making AVP TC, which served as a faithful sequel to the Alien vs. Predator movies. Its levels somewhat resemble those from the 1999 video game Aliens versus Predator and Alien Trilogy in style. In the mod, players assume the role of Duke Nukem, here depicted as a USCM private, as he embarks on a quest to eliminate both the Aliens and the Predators on both LV-426 and Earth.
A sequel to AVP TC was also released, known as the AVP 2 TC. In this mod the player notably assumes the role of a Predator, and the conversion features many references to the Aliens and Predator comics from Dark Horse Comics, including Bad Bloods (from Predator: Bad Blood), "Bugmen" (from Aliens: Colonial Marines) and Soviet soldiers (from Predator: Cold War). At the moment, only a Base Pack, consisting of three levels, is available.
Compared to the various DOOM total conversions, which typically recycled in-game sounds from Aliens, Predator and Predator 2, the many Duke Nukem 3D total conversions used sound files taken from the video games Aliens versus Predator and Aliens versus Predator 2. Many other assets from these games were also reused, including weapons, generic objects and the environment.
At least one Aliens-themed total conversion project was initiated for the video game Quake. However, 20th Century Fox closed the project down and sold the rights to Rebellion, which ultimately led to the development of Aliens versus Predator.
- It is somewhat ironic that there are so many Aliens-themed modifications for DOOM, as when id Software began developing the game it was intended to be a licensed product based on Aliens. However, this plan was later abandoned in order to allow the development team more creative freedom.
- Justin Fisher was offered employment by DreamWorks Interactive to help them work on their game, Jurassic Park: Trespasser (which was inspired by Aliens TC), an offer he rejected in order to finish his university degree.