From Wikipedia Sonic the Hedgehog 2 (or simply as Sonic 2) is a platform game developed in the United States by members of Sonic Team working at Sega Technical Institute, 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 (Sega nicknamed the American and European release date, a Tuesday, "Sonic 2sday"). It is the sequel to Sonic the Hedgehog and was followed by Sonic the Hedgehog 3 in 1994. The game introduces Tails as a new playable character.