Doom

Doom is a first-person shooter video game released on December 10, 1993 by id Software for MS-DOS, designed by John Romero, Tom Hall and Sandy Petersen with programming by John Carmack, Romero and Dave Taylor. Players take the role of an unnamed space marine fighting through hordes of undead humans and invading demons, beginning on the moons of Mars and ending in hell itself, rendered with a technique that combined a three-dimensional environment with two-dimensional sprite-based enemies and objects. Though not the first game in its genre, Doom is widely called the father of the first-person shooter for the scale of its cultural and commercial impact, and it brought competitive deathmatch play and early online multiplayer gaming to a mass audience. Id Software distributed the first of its three episodes free as shareware to drive sales of the full game, a strategy that helped establish shareware and online distribution as viable business models; by late 1995 the game was reportedly installed on more computers worldwide than Windows 95.