SONIC RIDERS: ZERO GRAVITY UNLOCKABLES
Chaos Emerald
Pass all missions from both Heroes & Babylon with extreme.
Heroes
Win all story missions to unlock Cream the Rabbit, Rouge the Bat, Shadow the Hedgehog and the Magic Broom.
Babylon
Complete all Babylon story missions to unlock Dr. Eggman, Silver the Hedgehog, Blaze the Cat, SCR-GP and the Angel/Devil
Amigo, Nights and Billy
Beat all the missions to unlock Amigo, Nights, and Billy. It doesn't matter what score you get just beat all of them.
Astral Babylon
Complete Babylon Story
Crimson Crater
Complete Crimson Crater in Babylon Story
Gigan Device
Complete Gigan Device in Babylon Story
MeteorTech Sparkworks
Complete MeteorTech Sparkworks in Babylon Story
Mobius Strip
Complete Babylon Story
Nightside Rush
Complete Nightside Rush in Babylon Story