You can play as either Sonic, Tails, Knuckles or Amy. Each character takes you to each exact level opening an extreme case of repetitiveness. Seven zones of brain numbing fun. Seven Chaos emeralds almost impossible to get. Which is odd because the game itself is ten times easier than traditional 2D sonic games and the Chaos Emeralds which are ten times harder to get than traditional 2D sonic games.
The saving point for this is the Tiny Chao Garden, which can hook up to the Gamecube and SA2B. But then i wish i had only got a rom of this.