Brian unlocked one hidden character on Sonic Riders

I unlocked one hidden character on Sonic Riders. His name was Dr. Eggman. I have to unlock NiGHTS, AiAi, and Ulala to clear all 100 missions. I have to unlcok E-10000G after 50 hours of gameplay. And I have to unlock Super Sonic to collect all gold emblems in Mission Mode. It was last Friday with Mommy, too.