Quake is 25 years old

It's 25 years to the day that iD software released Quake, the classic first-person shooter featuring a fully 3D world (including characters!), mouselook (not enabled by default!), and an outstanding soundtrack by Trent Reznor.

Until Quake, state-of-the-art first-person shooter games on PC generally used 2.5D graphics techniques to simulate height and depth while usually restricting player movement to a two-dimensional plane.