Sonic Riders cheats and cheat codes for Gamecube

Unlockable Characters:
Unlock Cream - Win Hero Story
Unlock Eggman - Win Babylon Story
Unlock Rouge - Win Hero Story
Unlock Shadow - Win Hero Story

Unlock Sega Carnival track:
Beat the Heroes Cup with a Gold Emblem

Unlock Sega Illusion track:
Beat the Babylon Cup with a Gold Emblem 

Unlock Random character:
Press R1 at the character selection screen

Extra missions:
Finish the Hero storyline to unlock Storm's missions. 

Finish Red Canyon or Night Chase in the Babylon story line to unlock 
Wave's missions. 

Finish Wave's and Storm's missions (including Sega Carnival and 
Sega Illusion tracks) to unlock Jet's missions. 

Extra music:
Finish the following tasks to unlock extra music in the "Audio Room" menu. 

Catch Me If You Can: Finish the Babylon storyline.
Theme of Babylon Garden: Finish Hero storyline.
Theme of Digital Dimension: Finish Babylon storyline.
Theme of Sega Carnival: Unlock the Sega Carnival track. 

Unlock Chaos emerald gear:
Get gold on every mission in mission mode.

Unlock Super sonic:
Use chaos emerald gear on sonic

Bonus cars:
Finish the Hero storyline - Unlock Shadow's Darkness jet shoes, Rouge's 
Temptation board, and Cream's Smile board. 
or/and
Finish the Babylon storyline - Unlock Sonic's Blue Star II board, Eggman's Egg-
Rider scooter, and the Magic Carpet.