Sonic the Hedgehog 2

Sonic the Hedgehog 2 is a 1992 platform game published by Sonic Team and licensed by Sega for their Sega Genesis video game console. The game features the first playable appearance of Miles "Tails" Prower, a fox with two tails, as Sonic's sidekick. The game features eleven zones, which are much larger than in its predecessor. The game was released on November 24, 1992 in North America, which was dubbed "Sonic 2sday" by the media and by gaming magazines. The game has sold over six million copies, making it the second-best selling game on the Genesis behind the original Sonic the Hedgehog. As such, it has been included in many compilation games over the years on a variety of platforms, such as the Sega Saturn, Nintendo GameCube, and even on mobile phones.

When the game is locked on to Sonic & Knuckles using the latter game's "Lock-On Technology", a game called Knuckles the Echidna in Sonic the Hedgehog 2 is available. As the name suggests, you play as Knuckles through the game's levels.