Project Einherjar

Project Einherjar is a single-episode total conversion for GZDoom/Doom 2 developed and released by Impie in the summer of 2016. It is set during nuclear winter, and features 7 new maps and a totally replaced roster of weapons and enemies in a Wolf3D style. Impie made the mod as a promotional gimmick for a sci-fi novel, The Helios Legacy, set in the same universe. The gameplay involves lots of fast, brutal shootouts with enemies that die relatively easily, but can badly injure the careless player.

Story
The player takes control of the novel's protagonist, Juno, in the postnuclear nation of Midgard, which stores its male population like cattle in "Valhalla" facilities. Under direct orders from the government, Juno has begrudgingly rounded up all known homosexual males in her Valhalla and delivered them personally to Gaulheim, to be experimented on by the homophobic Dr. Gaul. Juno is about to leave when a runaway male explains that Gaul is turning the men into mindless super-soldiers as part of a coup to take over the government. Juno reports this to her superior in the capital city, but Dr. Gaul is too well connected to move against officially. Instead, Juno is given permission to discreetly liquidate Dr. Gaul and her super-soldier program, Project Einherjar, while a blizzard cuts Gaulheim off from the rest of civilization.

Weapons
Project Einherjar completely replaces the player's arsenal.
 * Ballistic Knife - Juno's signature weapon, a knife that fires the blade like a small harpoon. The blade must be retrieved after each shot, but she can collect extra blades during the episode.
 * RavenM40 - A fast-firing and highly damaging pistol.
 * Shit Creek Scattergun - A slow shotgun Juno constructed from water pipes and other junk. A last-ditch resort for getting a better gun.
 * Thunderhammer Auto-Shotgun - A fully automatic version of the shotgun.
 * Gungnir M14 - A fast, deadly, and accurate assault rifle. It can usually hit its mark at long distances even on full-auto.
 * Dessler Frag Cannon - Pump-action rocket launcher. It fires more slowly than the Doom 'Launcher, to balance the squishy and mostly human enemy roster.
 * Uzi - An overpowered bonus weapon that is only accessed via cheating.

Enemies
One distinguishing feature of the mod is that it can be summarized as a gender-swapped Wolfenstein 3D; the boss characters even have large, distorted anatomy much like the bosses of Wolf3D and Spear of Destiny. Most of the enemies are female soldiers in the service of Dr. Gaul and her city sheriff, Althea Rourke, and each enemy type has a unique personality to distinguish it from the rest of the cast, from the sweetly chiding MommyBots that sedate intruders with morphine, to the valley-girl army recruits that mostly flee from combat, to the abusive and patriotic special forces troopers that go in guns blazing.

Most enemies use hitscan bullet attacks, with the exception of the Gaulheim Fratboys, which fire plasma balls; and the MommyBots and Vampire Docs, which fire morphine syringes that poison and slow Juno for a time. Both the Einherjar and Dr. Gaul can fire lethal rockets.

Other notes

 * It is one of the few Doom mods that make heavy use of a snowy environment.
 * Players are encouraged to use jumping and crouching to reach extra items and take advantage of cover during firefights.
 * The TC comes with a pdf "instruction manual" that details the story, items, and characters. The mod's plot is a spin-off story that is not directly connected to the plot of the novel, with the exception of a reference to how Juno lost her eye, her use of a ballistic knife, and her ability to improvise weapons on the go.
 * Many of the locations, names, and weapons are taken directly from the novel's universe, especially the use of Norse mythology (Fenris, Einherjar, Valhalla, etc).
 * The action-oriented mod is a bit of a genre-shift from the novel, which is more of a character-driven western. However, in both projects Juno is portrayed as an elite soldier capable of taking down large groups of enemies at one time.

Levels
Project Einherjar
 * MAP01: Checkpoint Charlize
 * MAP02: Human Processing
 * MAP03: Administration
 * MAP04: Conversion Center
 * MAP05: Garden of Calm
 * MAP06: Sorority of Pain
 * MAP07: Malpractice