DARK FORCES / Lucasarts / PC
Dark Forces is Lucasarts' unapologetic Doom clone from 1995, though they do add 3D rendered objects and cutscenes to the mix (both of which look exactly like the art style of Full Throttle.) Otherwise it pretty much looks, feels, smells, etc. exactly like a Doom total conversion mod more than a completely original game.
Mid-90's PC shooters have their charm, and some are still playable and enjoyable today, but there's a lot about them that has aged absolutely terribly, and makes them really hard to come back to after getting used to even the conveniences of an early 2000s shooter. Unfortunately, Dark Forces is like one long parade of stuff best left behind. Keycard fetch quests and godawful code-hunting puzzles that require epic heaps of backtracking and hunting for obscure little secret entrances and doors. Primitive automapping that can only display the level you are currently on with no detail other than chunky wireframes. Having to press PGUP and PGDOWN constantly to slowly look up and down at foes that are on higher and lower levels than you, and have no aim delays slowing them down. Slogging through heaps of the same foes over and over and over and over. Predictable-yet-cheesy difficulty techniques such as a horde of enemies waiting to jump you when you go through nearly every door or up nearly every elevator. And having to rely on iffy auto-aim.
It was only the third level - a rather nauseating slog through mazelike sewers as Sarlac Poo Monsters who can kill you in one hit keep popping up - that I started abusing the LASKIP cheat code due to the boringly complicated maps and overabundance of samey foes, and there were maybe like five levels total that I actually stopped and wanted to play all the way through. Compounding this is a system that refuses to let you save the game mid-level, instead giving you a series of (unmarked) checkpoints and three lives to navigate the level with. If you die, everyone you've killed so far on the level stays dead, but if you died due to lack of ammo, you respawn with no ammo, so you're kind of fucked. And if you lose all three lives it's all over and you have to start the whole thing over again. With more enlightened map design I'd be fine with this system, but given the absolute hordes of enemies you have to plow through all the time, and all the cheap "gotcha" ambushes around nearly every corner, it quickly becomes obnoxious.
* Gameplay Video