Trade milage points to buy things from the Shop:

Effect - Code

Tour Sounds - Pay 1000 mileage points
Character Voices - Pay 1000 mileage points
Cruise Mileage Secret 1 - Pay 500 mileage points
Cruise Mileage Secret 2 - Pay 500 mileage points
Aquarium Secret - Pay 500 mileage points
Orb Shop Secret - Pay 500 mileage points
Team Secret - Pay 500 mileage points
Birdo (playable character) - Pay 1000 mileage points
Dry Bones (playable character) - Pay 1000 mileage points
Brutal difficulty - Pay 1000 mileage points
King of the River (minigame mode) - Pay 2000 mileage points
Stunning Background - Pay 2000 mileage points
Staff Records - Pay 3000 mileage points
Ice Moves (Rare Minigame) - Pay 3000 mileage points
Stick and Spin (Rare Minigame) - Pay 3000 mileage points
Annoy Mode (All Taunts) - Pay 500 mileage points
Map Sounds (Solo Cruise Only) - Pay 1000 mileage points
Souvenir Secret - Pay 500 mileage points