You finish all of Storm, Jet, and Wave's missions. You don't even have to get gold on any of them, just complete them. When that is finished, you will unlock Nights, Aiai, and Ulala.
you play all misson thingyobobs
Complete all the missions
she spins the opponents and makes them dizzy
Clear all missions in mission mode
Complete all missions to unlock Ulala, Aiai and Nights. For Sonic Riders: Zero Gravity, complete all missions to unlock Nights, Amigo and I think Billy Hatcher, I have them unlocked I just haven't played the game in ages.
Same with NiGHTS and Billy Hatcher. Complete all the missions
Sonic riders, Sonic Riders: Zero Gravity and Sonic Free Riders already exist.
There are: Dr.Eggman, Shadow,Rouge,Cream,AiAi,NIGHTS,Super sonic,Ulala,E-100000G, and,E-100000R.
Sonic Free Riders is the third instalment in the Sonic Riders series.
sonic riders: free riders
Sonic Riders Extreme is an unconfirmed game at this stage.
No, but he is in Sonic Riders: Zero Gravity.