Complete the indicated task in Planet Superstars mode to unlock the corresponding character.

Alex Kidd: Complete Tournament Singles in the "Alex Kidd" stage.
Amy Rose: Complete Tournament Singles in the "Sonic The Hedgehog" stage.
Gilius Thunderhead: Complete Tournament Singles in the "Golden Axe" stage.
Gum: Complete Tournament Doubles in the "Jet Set Radio" stage.
MeeMee: Complete Tournament Singles in the "Super Monkey Ball" stage.
Pudding: Complete Tournament Singles in the "Space Channel 5" stage.
Reala: Complete Tournament Singles in the "NiGHTS" stage.
Shadow the Hedgehog: Complete "Tournament Doubles" in the "Sonic The Hedgehog" stage.