Descent

Descent is a first-person shooter where you pilot a ship through 30 underground mine levels in full six-degrees-of-freedom movement. You can pitch, yaw, roll, and strafe in any direction—up, down, sideways—while fighting robots that have overrun a lunar mining facility. The game's defining mechanic is complete spatial freedom: mine shafts drop vertically, tunnels twist at odd angles, and enemies attack from every surface. Combat happens in tight, disorienting spaces where walls become floors. Supports head-to-head and cooperative play via modem (two players) or network (eight players). If you want a shooter that ditches flat ground entirely, this delivers that specific challenge.