Sonic the Hedgehog is a 1991 video game, the first to feature Sonic the Hedgehog on the Master System and Game Gear consoles. Like its superior version, the game saw Sonic run across South Island to defeat Doctor Robotnik and free his friends from Badniks.
Similarities to the Mega Drive version
Both "first" games star Sonic as he fights Robotnik, who comes to attack at the end of the third act of most levels. All of Sonic's animal friends are present, including Sally Acorn, Johnny Lightfoot, Porker Lewis, Joe Sushi and Tux. Three levels from the Mega Drive version return (Green Hill Zone, Labyrinth Zone and Scrap Brain Zone). Some Badniks have moved location, with Roller and Bat Brain being removed altogether. Power Rings, springs all feature.
Differences to the Mega Drive version
Marble Zone, Spring Yard Zone and Starlight Zone are all replaced with Bridge Zone, Jungle Zone and Sky Base Zone. All Badniks are reused except for two obsolete models. The third act of each level is nothing but a quick run to a boss fight. Chaos Emeralds are found within each Zone, rather than in the Special Stage. Obviously, graphics have been altered to work with each console. The soundtrack was composed by Yuzo Koshiro.
This game was never directly adapted into a story, although certain elements made it within individual strips. Apart from the ones offered by the Mega Drive version, the Jungle Zone featured in Secret Weapon, years after it appeared in the game. A Sky Fortress also appeared early on, perhaps a combination of Sky Base and the Wing Fortress.