In 1994, Edge Magazine published a review for Doom, a first person shooter game, which ended with the reviewer lamenting how you could only fight with the game's enemies. "lf only you could talk to these creatures, then perhaps you could try and make friends with them, form alliances… Now, that would be interesting." Well it seems that the reviewer has gotten their wish, as someone has made a mod for the game that lets you make a Doom visual novel.
Even while the game was still just a freeware title, the modding community was already hard at work making fan-made content. Players talked about the Aliens total conversion mod just as much if not more than Doom II, which was released around the same time. Today, the modding community for Doom is still going strong with several new level packs released every year. A number of new gameplay modes and weapons are still being worked on. With the release of this modification to the Doom engine, it's likely that even more fan content for the game will be made.
The mod runs with ZDoom and GZDoom and, with a little tinkering, Zandronum 2.0, though you also need a copy of Doom II for the mod to work. It's still a work in progress with some improvements planned, but it's functional enough for someone to make a full game with. The visual novel features mixed with the Doom controls give the engine more functionality over other VN engines such as Ren'Py. At the moment, only a tech demo has been made, but since most of the source code doesn't need to be touched to make a new story, it shouldn't be long before the first full title is released.
Since plenty of mods that change the ascetic aspects of Doom already exist, it's already possible to make visual novels based on other popular franchises such as Super Mario, The Simpsons, or even Ghostbusters. With the help of programs for sprite editing, the possibilities are nearly endless. Though I imagine many will wish to keep with the vanilla Doom textures.
What sort of stories would you like to see come out of this mod? Perhaps a Doom dating simulator?