Replace all Pearls with Fish King coins
Press Select during game play on any level with Pearls, then hold L1
press Circle, X, Circle(3), X, Circle(2).
Hint: Chapter 3: Pearls:
If you attack a puffer fish, many pearls will come out.

Attack mode on at all times
Press Select during game play, then hold L1 and press Circle(4), X,
Circle(3) or Circle(4), X, Circle(4).

Two extra Clams and fame
Press Select during game play, then hold L1 and press Circle(2),
X(2), Circle, X, Circle(2).

Completing dance mode
To complete dance mode easier, press X + Circle + Triangle + Square
on each arrow It will count as the arrow that is pointing to, even
doubles.

Chapter 9: Staying hidden
When you must sneak around the fish with lights on their heads or
the ones with torches, there are some tables with cloths on them
that you can go under without being detected.

Chapter 9: Avoid being caught
To avoid being caught by police fish, go into houses until the cops
pass.

Shorties
If you cannot win the Shorties, try following them.