Sonic Rivals takes place, for the most part, on Onyx Island, in 6 stages called Zones. Each zone is made up of three stages, with the last being a boss battle. These are called, in order:
- Forest Falls Zone
- Colosseum Highway Zone
- Sky Park Zone*
- Crystal Mountain Zone
- Death Yard Zone
- Meteor Base Zone
*Sky Park Zone, unlike the others, has no boss battle associated with it, and is thus only made up of two Zones. There are four characters in story mode, all of whom do the same levels in the same order. The story is rather simplistic, as detailed in the instructions manual:
A mysterious land mass called "Onyx Island" suddenly appears in the south seas as if out of nowhere... The super-fast Blue hedgehog, Sonic, and his best buddy Tails head off to search for clues as to what might have transpired.
They run into Eggman, who reveals that he is in possession of a camera that can turn people in to cards. He shows Sonic a card of Amy Rose, and then proceeds to turn Tails into a card as well. Knuckles appears, and Eggman turns to him, holding up a card with a picture of the Master Emerald on it. Eggman flees, and Sonic and Knuckles agree to a race to see who can catch him first. As stages are completed, cards are awarded. These cards are collectible, and unlock new costumes for the characters, and some even unlock a secret character.