Mario Superstar Baseball/Unlockables

Ballpark

 * Koopa Castle - Clear Challenge mode on Mushroom level

Characters

 * Monty Mole - Clear Challenge mode as Mario
 * Toadette - Clear Challenge mode as Peach
 * Dixie Kong - Clear Challenge mode as Donkey Kong
 * Baby Luigi - Clear Challenge mode as Yoshi
 * Petey Piranha - Clear Challenge mode as Wario
 * Hammer/Fire/Boomerang Bro - Clear Challenge mode as Bowser

Minigames

 * Star Dash - Clear Challenge mode on Mushroom level with Koopa Castle
 * Mario Grand Prix - Clear all mini games on Star level

Challenge mode

 * Bowser as captain - Clear Challenge mode on Special level