I don’t categorize Descent as an FPS. It’s more a space-shooter. It was one of my favorite games growing up, that, and TIE-Fighter. Descent was very much in the realm of Wing Commander and TIE-Fighter but inside Doom Levels. Space-sims have always had weird physics as part of the charm (much to the hatred of the developers). Wall Running (strafe running), Rocket Jumps, Roll-Turns, things that are side-effects of non-uniform physics or physics effects that added to the gameplay so it was left in.