1991 in video gaming

Nintendo
While Nintendo initially dominated the market with its' 8-bit Nintendo Entertainment System, released in 1985, SEGA gained momentum when its' 16-bit Genesis machine hit the market in 1988. Facing loss of marketshare and an aging console, Nintendo reluctantly designed a new machine. Ten months after the Super Famicom was released in Japan, Nintendo replaced the Nintendo Entertainment System with the SNES in America. The system, which would go on to sell over 49 million units worldwide, included Super Mario World and retailed for US$199.
 * Super Nintendo Entertainment System
 * United States - August 13

Notable software releases
Unknown dates:
 * Street Fighter II (Arcade)
 * The mega-popular fighting series receives an overhaul.

March:
 * March 4 - Space Quest IV: Roger Wilco and the Time Rippers (PC)
 * The fourth Space Quest adventure sees Roger Wilco travel in time, both back to a prior game in the series and forward to a fictional future game.

June:
 * June 23 - Sonic the Hedgehog (game) (Genesis)
 * A fast-paced side-scrolling platformer, Sonic was designed as Sega's new mascot to steal thunder from rival Nintendo's Mario character.

July:
 * July 19 - Final Fantasy IV (SNES)
 * This Japanese RPG finds Cecil Harvey uncovering a plot to steal the Crystals of the world.

August:
 * Unknown day - SimCity (SNES)
 * The wildly-popular city-building simulation receives a release for the new home console.


 * August 13 - Super Mario World (SNES)
 * New to the classic Mario series were Yoshi and the Super Feather, a Raccoon Suit-like powerup giving Mario a cape and allowing him to fly.


 * August 15 - Ninja Gaiden (as Shadow Warriors, NES)
 * Shadow Warriors was the European release of Ninja Gaiden.


 * August 29 - ''Super Mario Bros. 3 (NES)
 * The final chapter of the Super Mario Bros. saga to grace the NES is released in Europe.

November:
 * November 1 - Ninja Gaiden (Game Gear)
 * Beat 'em up action on the go was the focus of this Sega release.


 * November 11 - Ax Battler (Game Gear)
 * A spin-off of Golden Axe, this hybrid adventure/action RPG was seen as a refined clone of Zelda II, featuring random battles with a side-scrolling perspective.