Sonic the Hedgehog 2, or simply Sonic 2, is a platform game developed by American studio Sega Technical Institute in collaboration with Sonic Team, and published by Sega for the Mega Drive/Genesis. It was released in Japan on November 21, 1992 and in North America and Europe three days later on November 24, 1992. It is the sequel to Sonic the Hedgehog and was followed by Sonic the Hedgehog 3 in 1994. The game introduces Miles "Tails" Prower as a new playable character.
The story follows Sonic the Hedgehog and his new partner Tails on their mission to stop the evil Dr. Robotnik from stealing the Chaos Emeralds to power his Death Egg. Sonic and Tails must defeat Robotnik's army and free their friends.
As of June 2006, it has sold six million copies. The game was compatible with Sonic & Knuckles lock-on feature which allowed the player to play as Knuckles in Sonic 2. It has been included in a number of compilation packages on a range of platforms; on June 11, 2007, the game was made available on the Nintendo Wii's Virtual Console, and released for Xbox Live Arcade on September 12, 2007.