There are currently nine playable all-star characters featured in the game that can be unlocked. These characters are split into three different teams and each team has one of the three different character types (speed, fly, or power).
Each team have their own individual skill, the Hero Team which is Sonic, Tails, and Knuckles is able to utilize invincibility and magnet powers. The Chaotix Team which consists of Charmy, Espio, and Vector gains you 10x rings, and the Dark Team which is made up of Shadow, Rogue, and Omega sees environments filled with golden enemies which cound as two normal enemies for a limited time.
HERO TEAM
Sonic
Character Type: Speed
Skills: Triple Jump and triggers Magnet and Invincibility Booster items for a limited time.
Unlock: Available from the beginning.
Tails
Character Type: Fly
Skills: Float and triggers Magnet and Invincibility Booster items for a limited time.
Unlock: Chapter 2
Knuckles
Character Type: Power
Skills: Dash Attack and triggers Magnet and Invincibility Booster items for a limited time.
Unlock: Chapter 3
CHAOTIX TEAM
Espio
Character Type: Speed
Skills: Triple Jump and 30% of Rings are converted to x10 Rings for a limited time.
Unlock: Beat level 3 of Green Hill and buy for 2,000 Rings.
Charmy
Character Type: Fly
Skills: Float and 30% of Rings are converted to x10 Rings for a limited time.
Unlock: Chapter 2 and buy for 2,000 Rings.
Vector
Character Type: Power
Skills: Dash Attack and 30% of Rings are converted to x10 Rings for a limited time.
Unlock: Chapter 3 and buy for 2,000 Rings.
DARK TEAM
Shadow
Character Type: Speed
Skills: Triple Jump and turns enemies into Golden enemies,
which count as two normal enemies, for a limited time.
Unlock: Beat level 3 of Green Hill and buy for 2,000 Rings.
Rouge
Character Type: Fly
Skills: Float and turns enemies into Golden enemies,
which count as two normal enemies, for a limited time.
Unlock: Chapter 2 and buy for 2,000 Rings.
Omega
Character Type: Power
Skills: Dash Attack and turns enemies into Golden enemies,
which count as two normal enemies, for a limited time.
Unlock: Chapter 3 and buy for 2,000 Rings.