MarsDoom

MarsDoom is a partial conversion for Doom II. The wad was created by Berthold Beckschaefer and Thomas Lokum, and was later legalized by Sparky of KISS Software. Currently the only version available is a preview version, which contains about 9 levels that were probably going to be from the completed project.

Story
After the events of Doom II, the UAC have scrapped all teleporter technology and abandoned their research bases. The research was unofficially continued with the additional bonus of studying the demonic. This proved to be too tempting. After the next six or seven months of quietly-conducted research, all contact to the UAC mars base, where the research was being done, became unavailable. A day later, Eileen O'Hara, daughter of the scientific coordinator of Mars base, sent a distress signal to the UAC when it was still discussing possibilities. They answer the signal by sending Doomguy off to Mars to take care of the Hellspawn once again, rescue any survivors, and arrive back in one piece.

Changes
The game was drastically changed, and featured turrets that would fire at the player unless deactivated, new enemies, and many impressive map tricks not often seen in a WAD created before 2001. A couple of levels required the player to escort someone else to the exit before the player himself could exit the level. There is some nudity, although it is only apparent for a certain person that the player must escort to the end of a couple of levels. Due to the many changes via Dehacked, the Zombieman, Shotgun Guy, and Heavy Weapons Dude are absent from this WAD, although a ZDoom version is rumored to contain them.