In case you're not being sarcastic, it is an old first person shooter where you fly in a kind of spaceship through labyrinthine mines and fight against rogue mine robots. It was defined by six degrees of freedom which made it very hard to orient yourself but which also made it stand out amongst other shooters.
I played the first two Descent games on an early VR headset with rudimentary head tracking and 30 Hz displays. They could make you sick just playing on a normal monitor. But in VR it was a literal pukefest. It was awesome!