Sonic the Hedgehog 2 is a side-scrolling platform video game released for the Sega Master System and Sega Game Gear by Sega. This game was released on the Master System in Brazil on October 25, 1992, a whole month before the more famous Megadrive version got released in Japan. The Game Gear version was released in Europe on October 29, 1992. It was released in North America in November 1992, and in Japan on November 21, 1992. This is the game where Miles "Tails" Prower made his worldwide debut. But he wouldn't be as well known, nor would he be playable until the Sega Megadrive and Sega Genesis versions came out.

The story has Doctor Ivo Robotnik (Doctor Eggman in the Japanese version of this game) kidnap Tails, Sonic the Hedgehog's best friend and surrogate brother, for ransom. Doctor Robotnik wants the six Chaos Emeralds from Sonic in exchange for the young fox.

Many people did not like the vertical scrolling aspects of this game. It was very difficult as "cheap hits" came often in this game, and there wasn't enough of the stage seen at the time to make a reaction to what is happening. This problem was made worse in the Game Gear Version by the lowered resolution.

The increase in meg power allows Sonic to grab back rings lost. However, the rings can roll off the screen, so the player has to be quick. Item boxes are the same as the first game, and as usual, Chaos Emeralds are scattered throughout the stages. Each is found in one stage in each of the first five zones. A sixth is rewarded if you destroy Silver Sonic in the sixth zone and have the first five emeralds. Having all six emeralds allows you to access the final stage and beat Doctor Robotnik as the final boss. If you complete that said task, you get the good ending. If you fail to collect all of the emeralds, the game ends after Silver Sonic's destruction.

There are seven zones total, each with three acts. The third act has zero rings and the boss.

The lower resolution is the first difference between the Game Gear and Master System versions. The Scrambled Egg music plays in the prelude, and the title screen has the music that was played in the prelude in the Master System version. The Underground Zone Boss seems to be more difficult due to the lowered resolution. The color of the water in the Aqua Lake Zone Round 2 is now a dark blue instead of green. The Green Hills Boss does his thing on a steeper hill, and the escape chute cannot be seen while fighting Eggman in the final zone.

The Game Gear version does not have Speed Shoes, while the Master System version does.

List of zones:

• Underground Zone
• Sky High Zone
• Aqua Lake Zone
• Green Hills Zone
• Gimmick Mountain Zone
• Scrambled Egg Zone
• Crystal Egg Zone (Only accessible if you have all six Chaos Emeralds)