Descent

If you ever wanted to feel like you were trapped in a washing machine armed with lasers, Descent is your game. Released in 1995, this claustrophobic, six-degrees-of-freedom shooter throws you into twisting tunnels where "up" and "down" are more like vague suggestions than actual concepts. You'll blast through robots, spin uncontrollably until you’re dizzy, and then spend half an hour trying to find the exit door. It’s part FPS, part space sim, and part exercise in motion sickness. Once you master the controls, though, the sense of liberation is unmatched—provided you don’t mind being hunted by angry drones in a maze designed by someone with a grudge against human orientation.