^What he said.
For its time, Descent was revolutionary. Full 360 degrees of movement, not to mention the robots being rendered as 3D models rather than sprites as was standard at the time. Yet the whole thing ran very smoothly, performing on-the-fly loading of nearby rooms to keep everything unbroken.
Basically, yes, you fly through mines, blowing up the computer-virus-infected mining robots, searching for the fusion reactor to blow up and then
run as fast as you can to the emergency exit. You can also rescue hostages for bonus points, but if you die, they die, and they can't be picked up twice. Exploration will reveal hidden rooms with more powerful weapons.
Very challenging: the enemies are pretty tough, even on lower difficulties, and the mines are huge 3D mazes, often with secret passageways and hidden traps. You do have a map that fills itself in as you go, but the darned thing gets a little difficult to read on the later levels. Length is good as well: there are 27 levels + 3 secret ones.
Had two sequels: Descent II and Descent 3. Descent II was pretty much identical to the first, but with more robots, more weapons, and more varied levels. Descent 3... I did not like very much, since it changed the graphics completely, replaced nearly all the weapons (with sucky ones), and the gameplay became puzzle-based rather than exploration/blowing **** up. It did have an interesting story, though, which the first two were lacking.
I love Descent and its sequel (although not the third), so I'm reccomending you get it.
