Monolith's Blood was an FPS that may not have been burdened with an excessively complex story, but it delivered a unique experience with a lot of fun, some very tongue-in-cheek humor, and plenty of references to classic cult horror icons.
The over-arching story from the first episode to the last is pretty simple. You're Caleb, the servant of an evil demigod who comes equipped your standard issue gravelly voice. The game begins with a cinematic of Caleb and his team being scolded by their demigod for failing it. They never reveal exactly what Caleb and his crew did for this being, nor do they provide a single detail about how they failed. Caleb emerges from the shallow grave to which he was confined and is now set on a course to destroy the evil being who took everything from him. This includes Caleb's love interest, Ophelia, the obligatory female member of the group. Each episode culminates in a boss battle with the monsters who were assigned to kill your friends.
Caleb slaughters his way through legions of basic horror FPS monsters like ax-wielding zombies, gun toting cultists, fire-breathing demon dogs, winged gargoyles, and venomous arachnids. His arsenal includes such staples as the sawed-off shotgun, Tommy gun, and dynamite, but it also features unique items like the hairspray-and-lighter flamethrower, a flare gun, Tesla cannon, and a voodoo doll. Pixelated blood and two-dimensional giblets fly freely from Caleb and all his adversaries. Expect to see a heaping helping of the red stuff sprayed over every encounter.
What really sets this title apart from its contemporaries were its little details and original touches. When some of the zombies are vanquished they're heads fall off. You can then kick them around the level for a while until they eventually pop from the repeated abuse. One level is a dark, twisted carnival with a working midway. There are some shooting galleries, and destroying the right targets leads to a “prize”, a special power up or weapon. One particularly interesting booth features a mouth that opens and closes and three zombie heads. If you can successfully get all three into the mouth you're rewarded with a temporary invincibility power up.
More unique touches come in the form of the countless horror references. The pub that shows up in several places is The Cask of Amontillado Pub, a reference to the classic tale of revenge from Edgar Allen Poe. There's also Pickman's rare book store, the namesake sourced from the works of H. P. Lovercraft. Caleb's non-sequiturs and witty quips are often quotes from everything from Sinatra songs to action movies. His first line in the first episode, as he emerges from his shallow grave, is “I live again” from Army of Darkness. Standing still for too long (while checking the map or just to make him say them) include him grumbling lines from “Strangers in the Night” and “My Way”. Further, some enemies join in the fun of references. One such example are the disembodied hands that will try to throttle our hero. The hand itself (as well as it's only line of dialog “I'll swallow your soul!”) are nods to Evil Dead 2.
Level design was also par for the course for the age. It's your basic hunt for doors and keys. They're not terribly complex, challenging but not frustrating. Some FPS titles of the era suffered from levels that were far too elaborate, with lots of back-tracking to find the correct keys which often saw the player chasing their tail for far too long. Or they were so simple they were unimaginative and strictly linear. This game manages to find a great balance between the two.
Over-all there's a lot to love about this dusty old game. More often than not, it's a fun little diversion. If you're looking for a nostalgic FPS, you can grab Blood: One Unit Whole Blood on Steam for a song. It has withstood the test of time remarkably well considering it didn't enjoy the kind of critical acclaim of its peers like Duke Nukem 3D or Doom.