Extra levels:
Beat all 150 regular levels, then select "1 Player" from the main menu. Then, select "The Final" option that appears to play the extra levels.

Cheat mode:
While playing a game, press L1 + L2 + R1 + R2 + Select on controller two to enable cheat mode. If you entered the code correctly, you will hear a sound. Then, enter one of the following codes:

Temporary invincibility:
While playing a game, press Right, Down, L1, R2, R1, Circle, Triangle, Square.

Temporary invincibility (PAL):
While playing a game, press R1, Circle, Triangle, Square.

30, 000 extra points:
While playing a game, press Square, Up, Down, L2, R1, Triangle, X, Triangle.

Bonus level:
While playing a game, press Triangle, Up, Triangle, L2, L1, L2, Square, X.

Toggle motion blur effect:
While playing a game, press Right, Circle, L2, Circle, R1, Circle, Square, Circle.

Toggle motion blur effect (PAL):
While playing a game, press Right, Circle, L2, Circle, R1, Circle, Square, Circle, Right, Down, L1, R2.

Chess Background:
While playing a game, press L1, Circle, Left, Right, L2, Left, R2, R2.