Descent is a topnotch FPS which should not be missed.
Descent puts you in a small ship called the Pyro GX. You play as a mercenary hired by the Post Terran Minerals Corporation, a megacorporation, to destroy mines infected by a computer virus which turned the robots there into deadily killing machines. The story contains zero twists throughout, but then again, Doom never really had a story, either. Descent, however, offers small explanations of every mine you are about to enter, as well as every robot, which is a little bit of something.
What Descent lacks in story, however, it makes up for in its offering of compelling gameplay in both its singleplayer and multiplayer modes.
The singleplayer game is excellent. Except for the first level, the mines you are thrown in are filled with deep, dark areas, as well as countless robots. The game also has a good sense of balance, as though you will battle hordes of robots in every level, you are also given just the right amount of powerups, and though a very small number of the powerups don't feel like they remain tactically useful throughout the game, they actually do. To top it off, every robot you destroy offers a satisfying explosion. :)
The multiplayer also offers a great amount of moments, though it's best with eight players. There is a substantial amount of variety in the multiplayer modes, all of which are fun. The only problem is, nobody plays it anymore.
Graphically, the game looked great for its time. Descent was one of the first games to offer both 3 dimensional levels and objects. And though the texturing doesn't live up to today's standards, and is occasionally unaligned, the robots, powerups, and levels look great.
The game offers some very memorable sound effects and music. Though the music is MIDI, it still sounds impressive and in-line with each level.
Finally, with so many levels and easy to use level editors available, the game's replay value is infinite.
To sum it up, Descent is a game you just have to play before you die. Though it may not work on a modern computer, you can easily download a port such as D1X or D1X-Rebirth to make it work. If you didn't play it back then, download an abandonware version or buy it off of eBay and play it now. You won't be disappointed.