Sonic 1 started it...
STORY: Continues right where Sonic 2 left us, the Death Egg crashed on the Floating Island, Eggman tricked the guardian of the island, and it's Master Emerald, (the controller of the Chaos Emeralds) Knuckles The Echidna, into thinking Sonic is a bad guy.
Sonic and Tails fly to find the Death Egg so they can finish off Eggman, Sonic goes Super and flys ahead, only to get hit by Knuckles, power down, and get the Emeralds stolen. Not cool.
Sonic and Knuckles eventually face off, and after being defeated by Sonic a third time, Eggman snaps, and begins work on something sinister...
This game is a three part game, this is the second of the trilogy: Sonic 2 being number 1 and Sonic and Knucles ending this story arc. It all fits great as well, all with no dialog, AT ALL. Amazing work, Sonic Team, bravo!
10/10
GRAPHICS: Slightly improved, still quite the same, it's also the first we see of the Sonic games having 2D done in a way that impersonates 3D. Nice.
All in all pretty much the same, awesome game bonus, go!
9/10
SOUND: Music is amazing, and the invincibility song is just...awesome...I sometimes hum the tune without even realizing, I swear.
9.5/10
GAMEPLAY: Sonic can now attack in the air, bounce with a water shield and homing attack with a fire shield, no joke. Just press jump twice. Improved gameplay, yes indeed.
9/10
OVERALL: This game is my favourite Sonic game, it's great. I love it. I have it even though I no longer have a Genesis, I love it that much.
10/10, no doubt about it!