The following stages, characters and courts are ALL unlocked in Planet Superstars mode when the indicated task has been completed.

Unlock Space Harrier Stage:
Complete Tournament Singles in the 'Space Channel 5' Stage.

Unlock Alex Kidd Stage:
Complete 'Get A High Score!' in the 'Space Harrier' stage.

Unlock Virtua Squad Stage:
Complete 'Hit The Big Zombies!' in the 'Curien Mansion' Stage.

Unlock Outrun Stage:
Complete 'Hit Justice Shots' in the 'Virtua Squad' Stage.

Unlock Alex Kidd as a Playable Character:
Complete Tournament Singles in the 'Alex Kidd' stage.

Unlock Amy Rose as a Playable Character:
Complete Mission 2 in the 'Sonic The Hedgehog' stage.

Unlock Gilius Thunderhead as a Playable Character:
Complete Mission 1 in the 'Golden Axe' stage.

Unlock Gum as a Playable Character:
Complete Mission 12 in the 'Jet Set Radio' stage.

Unlock MeeMee as a Playable Character:
Complete Mission 8 in the 'Super Monkey Ball' stage.

Unlock Pudding as a Playable Character:
Complete Mission 1 in the 'Space Channel 5' stage.

Unlock Reala as a Playable Character:
Complete Mission 2 in the 'NiGHTS' stage.

Unlock Shadow the Hedgehog as a Playable Character:
Complete Mission 14 in the 'Sonic The Hedgehog' stage.

Unlock Outrun Court:
Complete Exhibition Doubles in the 'Outrun' stage.

Unlock Sonic The Hedgehog Court:
Complete Exhibition Singles in the 'Sonic the Hedgehog' stage.