Radiant Emerald Course
On each normal course finish in first place.
Play as Dr. Robotnik
On the Radiant Emerald Course finish in first place.
Play as Super Sonic
From the first four courses collect all seven chaos emeralds.
Play as Same Character
In Multiplayer Mode highlight a character hold Change View and press Action.
Hold Action Accelerate Change View and press Start.
Press Action Accelerate.