All Levels/Items/Keys

At the world map enter circle cross triangle square right down up left
Then use select to bring up the sub-menu
Then use square plus select to add an item Use circle select to delete an item2.

Vulture Mode - fly higher and further using the X button
During play enter circle R1 R2 square right L1 L2 left.If this works you'll see a vulture icon
onscreen

Dolphin Mode - swim faster and stay submerged longerDuring play enter square square triangle
triangle cross crosscircle circleIf this works then you'll see a dolphin icon onscreen