This is a collection of retro FPS which I downloaded a long, long time ago. Below is an excerpt of the readme so you can see what's in the collection:
**1st Wave: **
-Battlezone + -Castle Master + -Cybercon 3 -Cyber-Cop -Eye Of The Beholder -Faceball 2000 -Hovertank 3D -Midwinter + -Mobile Suit Z Gundam - Hot Scramble -Space School Simulator - The Academy -Star Cruiser -Terminator 2029 -WaxWorks -Xenocide
**2nd Wave: **
-Alien Cabal -Bad Toys 3D -Blake Stone + -Bloodshot - Battle Frenzy -Bobenstein 3D (Demo) -Catacomb + -Corridor 7 + 8 -Depth Dwellers -Escape From Monster Manor - A Terrifying Hunt For The -Undead -H.U.R.L. -In Extremis -Isle Of The Dead -Ken's Labyrinth -Lethal Tender -Mr. Pibb: The 3D Interactive Game -Nerves Of Steel -Nitemare 3D -Operation Body Count -Pathways Into Darkness -Robocop 3 -Super Noah's Ark 3D -Terminal Terror -The Fortress Of Doctor Radiaki -The Terminator - Rampage -Thor's Hammer -Ultima Underworld + -William Shatner's Tek War -Wolfenstein +
**3rd Wave: **
-Alien Trilogy -Alien vs Predator -Alpha Storm -Ashes To Ashes - Feeding The Fires Of War -Assassin 2015 -Blood -Cybermage - Darklight Awakening -CyClones -Damage Incorporated -Descent + -Disruptor -Doom 64 -Duke Nukem 3D + -Eradicator -Fate (Demo) -(GZDoom) Action Doom 2 -(GZDoom) Blasphemer -(GZDoom) Chex Quest + -(GZDoom) Doom + -(GZDoom) Final Doom + -(GZDoom) FreeDoom -(GZDoom) HacX -(GZDoom) Harmony -(GZDoom) Heretic - Shadow Of The Serpent Riders -(GZDoom) Hexen + -(GZDoom) Strife -Immercenary -In Pursuit Of Greed -Jumping Flash! -Kileak - The DNA Imperative -Killing Time -Legend Of The 7 Paladins -Necrodome -Outlaws -PO'ed -Powerslave/Exhumed -Prime Target (Demo) -Quarantine + -Quiver -Rebel Moon + -Redneck Rampage + -Rise Of The Triad -Robotica -Shadow Warrior + -Star Wars: Dark Forces -System Shock -Terminator: Future shock + Skynet -The Elder Scrolls + -The Hidden Below -The Marathon Trilogy -Witchaven + -Wrath Of Earth -Zero Population Count -Zero Tolerance
** Obscene Wave: PORNOSHOOTERS**
-Duke Screwem -Immoral Cumbat -Rodger Ramrod (Demo)
Key: Pluses (+) indicate sequels/add ons of the games that are included (that I know of). GZDoom runs MULTIPLE games. They all are ran the EXACT SAME WAY, check GZDoom's GAMESETUP.txt file. Demos are marked by (Demo) at the end of the game title.