Join Sonic and Sega All-Stars in an all-new, high-speed, racetrack showdown. Explore stunning new circuits including Sonic Seaside Hill, Curien Mansion and Blizzard Castle as you zip around medieval castle ramparts, hurtle under lush rainforest canopies and tear through bustling cityscapes. Jostle against 20 challengers including Super Monkey Ball's AiAi, Amigo from Samba and the evil Dr. Eggman in your unique character vehicle. Stay ahead of the pack by dodging traps and launching outrageous character moves such as the invincible Super Sonic or the Banana Blitz assault of monkey balls. Battle it out in single player, challenge your friends in 4 player split-screen or compete in 8 player online action.