The following codes must be entered using controller 2.
All Levels, Items & Keys:
At the world map enter Circle, X, Triangle, Square, Right, Down, Up, Left. Press Select to bring up the Sub-menu, the press Square + Select to add an item, or Circle + Select to delete an Item.

Vulture Mode:
Fly higher & further using the X button. During play enter Circle, R1, R2, Square, Right, L1, L2, Left. If it works, you'll see a vulture icon on the screen.

Dolphin Mode:
Swim faster & stay submerged longer. During play enter Square, Square, Triangle, Triangle, X, X, Circle, Circle. If this works, you'll see a dolphin icon on the screen.