Descent, definitely. I never fully understood why it didn't take off the way it did. I sometimes catch myself imagining an alternate future where FPS games are referred to as "Descent clones".

Other games: Parkan: The Imperial Chronicles/Parkan: Iron Strategy, Battlezone/Battlezone 2: Combat Commander, and Uprising/Uprising 2, which all deserve some mention for trying to merge first person/vehicular combat and real-time strategy/tactics, to varying degrees. That particular genre never really got its due, in my opinion (perhaps for good reason, given the issues all of those games had with controls).

On that note, other similar games were Giants: Citizen Kabuto and Sacrifice (Hi Licurg!). A shame those two games didn't make more of a dent in the gaming industry.

Because Diablo was first hack & slash in real time.

Agreed I forgot about catacomb 3d

It depends on what you want to call "3D" and what you want to call "FPS". But if you want to really reduce it down to its core components, then Alkabeth (1979) is probably what would count.

If you want to count "fully 3D" then Quake would be the obvious choice, and if you want to actually define FPS as "you running in a corridor/rooms shooting people in real time movement along the x-y plane" then we have Wolfenstein 3D (1992) and Pathways into Darkness* (1993)

*You could make the arguemrnt that PiD wasn't a "pure" FPS but an FPS-RPG hybrid, potentially make it the first such game in that genre.

EDIT: Relevant: http://arstechnica.com/gaming/2016/02/headshot-a-visual-history-of-first-person-shooters/

I second this. and add morphing terrain to the list.

Midwinter

One of those interesting early genre mixes that sunk into obscurity. Someone is making a remake but I have no idea when that will be finished.


[url=https://en.wikipedia.org/wiki/Midwinter_(video_game)]Wiki entry[/url]

Mobygames entry


Gameplay videos:

https://www.youtube.com/watch?v=8JD83gl39-M

https://www.youtube.com/watch?v=18V1U3Cqei0

https://www.youtube.com/watch?v=kSZJ6LXczIQ

First thing that comes to mind is 1994's X-COM: UFO Defense. It always seemed to me like that game had no business being that ridiculously good with so much depth and replayability back in 1994. Is there any 'strategy' game even close to that caliber from that time apart from Civilization?

Another one is Dune2. For laying the template of the rts genre, it did have a surprising amount of depth to it. 3 Different factions which each differed wrt to at least one building, and radically differed wrt one unit and one special ability. You had upgradable production buildings that unlocked extra things to be constructed, you had space ports where you could look for special deals on military equipment, you had carryall aircraft that picked up damaged units and deposited them at repair depots. It is always seemed far too advanced for me for the first 'true rts'.
Then again, it made up for that by not having mouse support :P [edit: meant no drag select]

It played just fine with mouse. What kind of broken version did you play? All I can say I couldn't go back to its nowadays ridiculous requirement of infinite clicks: click to select (single) unit, click to choose order, click to carry out order... click click click.

Damn I'm tired :P Yes I meant it had no drag select!

Battlecruiser 3000AD.

Seconded, not to mention an original soundtrack composed by David freaking Bowie of all people, and even if I get burned at the stake for saying this, it's one of his best work. Even today I sometimes start singing "New Angels of Promise" out of the blue.

Adventure game, RPG, fighting game, FPS, it trascended genres in a way no game had done until then and few since; the thought of what Omikron would be if it'd been made today is mesmerizing. Truly a game decades ahead of its time.

I second that. The Nemesis system was like the only thing that game hd going for it. It wasn't for that it would just be Assassin's Creed: Mordor.

How about Fahrenheit? Haven't played Omikron: The Nomad Soul so I can't speak for that game, but Fahrenheit was very innovative at that time. It was more an interactive movie than a game and you played with a few characters that were on opposite sides, so you basically played against yourself.

And Prince of Persia: The Sand of Time? Sure Max Payne was first with bullet time, but Prince really took advantage of time control as a game mechanic and that was something not commonly seen in games till then.

While I loved Dune 2 and it did innovate in several areas, a lot of stuff it did is from Herzog Zwei for the MD/Genesis. For example, the carryall is basically an automated version of a function the player avatar has in that game. HZ is still quite different though, playing more like Dawn of War or Z, mixed with one on one mech combat.

https://www.youtube.com/watch?v=E3EaIIY_gkw

System Shock