The Post-Terran Minerals Corporation (PTMC) digs up minerals on all nine planets of the solar system, employing humans and robots to do its job. Unfortunately, the mining robots are now being controlled by a hacker, and have taken the human workers hostage. The PTMC has tried to get the robots back under their control, but communication with the mining stations has been lost. In desperation, the PTMC modifies a Pyro-GX ship for combat and hires a mercenary, codenamed "Material Defender", to fly it. The mission is to destroy the infected mines and rescue human hostages, destroying any hostile robot that gets in the way.
Descent is a 3D first-person game that puts the player at the controls of the Pyro-GX spaceship. The player travels through various interior locations (mines) but can do so in 720 degrees of movement. However, the ship only moves forward and backward in any direction it is facing. The ship is able to use a variety of weapons scattered throughout each level, including lasers, chainguns, shotgun-like energy weapons, plasma cannons, fusion cannons, concussion missiles, homing missiles, proximity bombs, smart missiles, and Mega Missiles.
The goal of each level is to locate and destroy the mine's reactor. Once completed, there are only 45 seconds to find the escape hatch before the mine explodes. As progress is made through the game, the AI will adapt to the player's strategies and attempt to prevent them from reaching their goals.