The second game featuring Sega's mascot Sonic the Hedgehog.

The evil doctor Robotnik wants to conquer the world. In order to do that, he imprisons and transforms all animals into robots. This way they can build his powerful weapon, the Death Egg. Along with your sidekick Tails you must collect all the Chaos Emeralds, free the animals and defeat Robotnik.

The game features 10 big zones in which you must defeat enemies and gather rings.

Everyones favorite hedgehog is back, Sonic the Hedgehog 2 follows the same useridea as before but adds a second player-controllable character in Tails the Fox and a split screen simultaneous 2 player mode - this was the highest selling Genesis title.

The nefariously evil scientist Dr. Ivo Robotnik is at it again with his demented goal to conquer the world by forcing innocent animals to become evil 'badniks' (robots), and only one speedy hedgehog is eager enough to put a stop to Robotnik's scheme and his name is Sonic The Hedgehog. and this time he's not alone, Miles Prower (miles per hour, get it?). The Fox who's commonly known as 'Tails' because he has 2 tails which enable him to fly has decided to tag along with Sonic in order to bring peace back to the planet.

Sonic 2 Delta is a hack which features restored deleted levels such as Wood Zone, Hidden Palace Zone, Dust Hill and Winter Hill.

This is a rom hack of Sonic 2.

In addition to restoring cut zones, the hack adds a few new features: The ring counter now shows how many rings remain in a zone, the level select menu has been updated to allow access to the new zones, some Sonic 3 graphics have been ported, and even Knuckles has been ported from Sonic & Knuckles!

Sonic 2 Long Version is a more complete version of Sonic 2, which makes it somewhat similar to Sonic 2 Delta. This hack features four levels originally scrapped during Sonic 2's development. No levels have been changed, only added.

The inhabitants of South Island are in danger! Dr. Robotnik has stolen all the Chaos Emeralds which kept the power balance. Robotnik has thrown the Emeralds in a parallel universe and is keeping the red one. Sonic and Tails must retrieve all the Chaos Emeralds before the destruction of South Island.

Play as Sonic or Tails in this platformer. Great graphics but the gameplay hasn't changed and it's all just too easy!

From slimy sewers to monstrous machine rooms. Dr. Robotmik's latest fortress is a giant pinball machine! Will it withstand a Sonic spin-vasion? Bounce from giant flippers and hissing steam vents. Rev through dizzying loops and up death-defying ramps!

Sonic stars in his own pinball game - as the ball! Unfortunately this conversion is far too easy to complete as you can move him around far too much in mid-air. Flipping' easy.

Sonic The Hedgehog spins into pinball pandemonium! Dr. Robotnik's latest robotic-creation factory is the Veg-O-Fortress, a volcanic island fueled by the Chaos Emeralds and protected by the Pinball Defense System. Strap on your Power Sneakers for all-new Sonic moves! Sonic rockets into space, spring launches from levers and balls up for a high-altitude bounce! Multi-round zones of wild Sonic action through glittering caverns, oozing toxic pools and boiling lava pits!

Amy Rose in Sonic the Hedgehog is a fan-made hack of the game Sonic the Hedgehog

Sonic Gaiden is a 2003 fan-made hack of the original Sonic the Hedgehog game for the Sega Genesis/Mega Drive.

The hack allows the option to play as either Sonic or as Mighty the Armadillo, who became popular as a founding member of the Chaotix crew. However, the difference between Sonic and Mighty is purely cosmetic.

The game features the ability to play as one of five different characters: Sonic the Hedgehog, Mighty the Armadillo, Shadow the Hedgehog, Miles "Tails" Prower, and Knuckles the Echidna. It is an extensive reworking of the original game, featuring new art, music, abilities, layouts, and other things.

The hack features Mighty the Armadillo, who appeared in both SegaSonic Arcade and Knuckles' Chaotix. Features include new art, palettes and layout for Green Hill Zone.

The hack is basically the same as the original game, except with a number of extra features and bugfixes.

South Island Adventure is a large scale hack of Sonic the Hedgehog featuring Espio the Chameleon. It has new sprites, several new levels, and numerous other alterations.

Tails in Sonic features Tails as a playable character instead of Sonic. Tails can fly, Spin Dash and swim in the same way that he can in Sonic 3.

Dr. Robotnik managed to capture all of the Chaos Emeralds, but an accident in the testing phase of his new ultimate weapon, the "Atomic Destroyer", scatters the Emeralds all across the island. While Sonic and Tails are out to retrieve them, they are cut short by Knuckles the Echidna. Robotnik finds the yellow Emerald first, and dupes Knuckles into believing Sonic and Tails are out to steal the Emeralds.

Additionally, a treasure hunter named Nack the Weasel takes advantage of the fact that they are all distracted with fighting one another, in order to take the Emeralds for himself. He does not know of the power of the Emeralds, only that they'd be worth a lot of money, so he sets out to take them for himself before the others do.

Contrary to the classic speedy gameplay in the Sonic series, Tails Adventures is a puzzle-based platformer with a strong emphasis on item collecting and backtracking, like a side-scrolling action RPG.

Tails can walk, jump, duck, look up, fly, hang on ledges, and can solve puzzles and defend himself with a range of different items, such as Hammers, various types of Bombs, and medallions bearing other characters, which allow him to perform additional actions, such as Spin-Dashing or punching enemies. His health is measured numerically by a Ring Item Box at the top left corner of the screen. HP is replenished by collecting Rings, which can be found by blowing up rocks or defeating enemies. He starts with 10 HP, but that number maxes out at 99 when all six Chaos Emeralds have been collected. His air time is limited by the flight gauge, which starts at about 3 seconds and maxes out at about 15.

Story:
While flying aimlessly on a solo adventure, Tails discovers a small island and lands to investigate. The island appears to be totally uninhabited except for mine cart tracks that weave around the landscape. Tails momentarily frets that Eggman may have some kind of discreet operations transpiring on the island, but his thought is interrupted when he notices the vibration of an approaching cart on the tracks. Sensing danger, he leaps into a nearby cluster of bushes just in time to see a gnarled old hag whiz by in a sparkling silver cart. The old woman, announcing to nobody inparticular, proclaims herself to be the great Witchcart, and claims the island and everything on it as her own, threatening to transform any dissidents into crystal. With a wild cackle, she calls her henchmen to the "flying machine" and is followed in short order by Carrotia, Bearenger, and Fockewulf. Tails, determined to free the animals of the island, emerges from his hiding place and gives chase to Witchcart and her minions.

Gameplay:
The gameplay of Tails' Skypatrol is less in line with the familiar platforming style of the traditional Sonic games. There are no rings or emeralds to be collected, Dr. Robotnik is entirely absent and Tails is constantly "suspended" in flight mode and clears each stage simply by completing each course from left to right. The screen is fixed and constantly moves along with him. Should Tails fall, bump into objects or touch the ground, he loses a life.

Across each stage Tails carries a golden ring with him which he can throw as a projectile to defeat enemies or break walls. Using the Ring, he will also latch on to any number of devices the player will encounter in each stage, ranging from gymnastics bars to rail carts.

In order to stay afloat, the player must constantly watch Tails' flight meter, which slowly drops to zero. Scattered across the map are Mint Candies which Tails can collect in usergroup of either one, two or three to replenish his stamina.