Games similar to Project Warlock include Doom. It's paid, but GZDoom is free. Other options are Shadow Warrior (Reboot), Prodeus, DUSK and Wrack: Exoverse. In total there are six First-Person Shooters like Project Warlock for Windows, Mac and Linux.
Doom is a science fiction horror-themed first-person shooter video game in which players assume the role of a space marine, popularly known as "Doomguy", who must fight his way through the hordes of invading demons from Hell.
United States
ZDoom is a family of enhanced ports of the Doom engine for running on modern operating systems. It runs on Windows, Linux, and OS X, and adds new features not found in the games as originally published by id Software.
Germany
EU
Shadow Warrior is a series of first-person shooter video games that focuses on the exploits of Lo Wang, a modern ninja warrior who fights through hordes of demons.
PolandEU
Prodeus is a first-person shooter of old, re-imagined using modern rendering techniques and technology. Experience the quality you’d expect from a modern AAA game, designed with retro aesthetics and gameplay that invoke the tech-imposed limits of older hardware.
Canada
Battle through an onslaught of mystical backwater cultists, possessed militants & even darker forces as you attempt to discover just what lurks beneath the Earth in this retro FPS inspired by the '90s legends.
United States
Wrack: Exoverse is the follow-up to the 2014 first-person shooter Wrack. It was a very fast-paced, arcade-style game with heavy influences from classic shooters like Doom and Quake.
United States
