Sonic the Hedgehog 2 (1992) is about the return of Sega's mascot, Sonic and introduction to the blue hero's friend, sidekick and surrogate brother Miles 'Tails' Prower.
Dr Eggman/Robotnik is at it again, attempting to take over the world with his army of robots (each one containing one of Sonic's captured friends as before), a deadly new weapon, the Death Egg and now he just needs the seven Chaos Emeralds to complete his plan. Naturally, Sonic simply can't stand by and let this happen, so he goes after the Doctor again, with Tails in tow to retrieve the Emeralds and put a stop to Robotnik's plan.
Sonic 2's gameplay is vastly similar to that of Sonic's previous adventure, a simple run and jump play-style while still maintaining the speed aspects of Sonic 1. It also introduced new opportunities of play with the introduction of Tails, such as the memorable Sky Chase Zone and the fact that Tails could spin his trademark twin-tails and fly, though players were not given control of Tails' unique ability until Sonic the Hedgehog 3 (1994). Sonic 2 also deviated from the rotating maze-style Special Zone of Sonic 1 and introduced a half-pipe style Special Zone where the player can retrieve a Chaos Emerald, a format still used in modern Sonic games such as Sonic Heroes. And this was the also the first that really introduced an incentive for collecting the Emeralds; Only when you had all of the Emeralds could you see the real ending (as in Sonic 1) AND transform into Super Sonic who was much faster and invincible as long as you kept collecting those rings. It was also the first Sonic game to introduce a multiplayer mode, where you could either race a friend in split-screen mode, or your friend could jump into the main adventure and control Tails any time.
Sonic 2 is well-renowned among gamers in general and Sonic-fans and is still regarded by many as a classic component of the early 90's gaming scene and some still refer to it as the greatest Sonic game to date.