Level Select:
At the world map screen, press Circle, X, Triangle, Square, Right, Down,
Up, Left on controller two.

Delete Items:
At the world map, press Select screen to display the menu. Then, press
Square + Select to add an item or Circle to delete an item.

Dolphin Mode:
While playing a game, press Square(2), Triangle(2), X(2), Circle(2). If
you entered the code correctly, a dolphin icon will appear. Then, your
character can remain underwater longer and swim faster.

Vulture Mode:
While playing a game, press Circle, R1, R2, Square, Right, L1, L2, Left.
If you entered the code correctly, a vulture icon will appear. Then, press
X to fly higher and further.

Team Doll:
There are a total of 23 team dolls hidden throughout the game. Each doll
represents a member of the development team. Find 10 dolls to activate
dolphin mode. This will allow your character to swim faster and jump out
of the water. Find 14 dolls to activate vulture mode. This will allow your
character to fly.