During any level where you get pearls press Z to go to the controller screen. Hold L and then input the codes, after you input the code release L and you will hear a chime to confirm the code.

Pearls are replaced with Coins: X, A, X, X, X, A, X, X
Enemies Fly off the screen with hit: X, X, X, X, A, X, X, X, X

Go to any chapter that's adventure and PRESS Z, HOLD L AND PRESS A,X,A,LEFT,LEFT,Y,R,DOWN,Y,Y