One day, Dr. Eggman had an epiphany: if Sonic's speed was removed from him, taking over the world would be like taking candy from a baby. So, later that night, Eggman snuck into Sonic's house and, rather than just kill him in his moment of weakness, replaced Sonic's sneakers with a pair of supposedly-identical-looking Speed Down Boots. Next morning, Sonic woke up, slipped on the shoes and found out that he couldn't run or even jump. Eggman made himself known and gloated that the Boots can only be removed by Chaos Emerald energy. He also claimed that the miracle gems are all hidden in the Great Labyrinth, his latest base. So, in a nutshell: Eggman took Sonic's speed; Sonic must go through a dungeon to get it back.
As far as gameplay is concerned, the best way to describe it is: Marble Madness with Sonic as the playable character. Sonic can't run or jump, only walk and your only means of fast locomotion and offense is the Spin Dash. There are four "worlds" in the Great Labyrinth: Labyrinth in the Sky, Sea, Factory and Castle, and they each have three acts and a boss battle. The main objective in each main act is to collect three keys and make it to the goal in three minutes. Get hit, and you lose time and the keys fly out of you; don't grab the keys in time and they'll pop right back in their original spots. Fall down a pit or right out of time, and you die. With boss battles, rather than collecting keys, you must first go down a chute and collect rings on the way down. Once you reach the end, you'll actually fight the boss. Get hit once, and you lose all of your rings - even if you manage to get 99 rings in the tube - get hit again, you lose a life. If you lose all of your lives, you must start from the beginning of the game.
- Big Bad: Dr. Eggman.
- Diagonal Speed Boost: For some reason, Sonic walks faster if he moves horizontally.
- Epileptic Flashing Lights: Anytime a item is in use, unfortunately. In some levels, getting a invincibility or speed power up makes the game practically unplayable due to all the flashing.
- Everything Is Better With Spinning: You do remember that Sonic can roll, right? This game won't let you forget that.
- Excuse Plot: Eggman slowed Sonic down with heavy boots. You must go through his labyrinth to remove them.
- Fate Worse Than Death: Dr. Eggman tries to do this to Sonic by removing his speed, but Sonic gets creative.
- The Hero: Sonic the Hedgehog, naturally.
- Invincibility Power-Up: The Twinkle powerup.
- Isometric Projection
- MacGuffin: The five/six Chaos Emeralds.
- Mecha-Mooks: Dr. Eggman's minions.
- Multiple Endings:
- Ending 1: You've cleared the game, "BUT IT IS NOT PERFECT!" Even though Sonic looks like he can run normally again, the game implies that you missed something in Stage 2-3.
- Ending 2: You've finished the game and got through the secret level. "IT IS PERFECT! WONDERFUL!" The ending is pretty much the same, but you get the Level Select code and no "TRY AGAIN" message.
- Oddball in the Series
- Pinball Zone: The whole game consists of this type of level, seeing as Sonic must use his Spin Dash to get around quickly. Some levels also use pinball flippers as gimmicks.
- Rolling Attack: The gameplay focuses on this technique.
- Secret Level: Hidden in stage 2-3.
- Springs Springs Everywhere
- Sprint Shoes: The Super Boots powerup.
- Super Speed: Subverted, unlike almost every other Sonic game before and since; the whole plot centers around Sonic's forced inability to go fast and his quest to regain it... by rolling around at the speed of sound.
- Video Game Settings:
- X Meets Y: Sonic the Hedgehog meets Marble Madness.