Enable all cheats:
Press L1(2), R2(2), L1, R2 at the pre-season team selection screen.

Big players:
Press L1(2), R1, Triangle, L1, R1 at the pre-season team selection screen.

Small players:
Press L1(2), R1(2), L1, R1 at the pre-season team selection screen.

Shadow players:
Press L1(2), R1, L2, L1, R1 at the pre-season team selection screen.

Short, fat players:
Press L1, Triangle, R1, Triangle, L1, R1 at the pre-season team selection screen.

Tall, thin players:
Press L1, Triangle, R1(2), L1, R1 at the pre-season team selection screen.

Fast player:
Press L1(2), L2, Triangle, L1, Triangle at the pre-season team selection screen. Use the speed burst button to run as fast as possible during the rest of the play.

Land mines:
Press L1(3) R1, L1(2) at the pre-season team selection screen. Land mines will be placed on the field.

Fumbles:
Press L1(3), L2, L1(2) at the pre-season team selection screen. The ball will be fumbled twice during every play.

No fumbles:
Press L1(3), R2, L1(2) at the pre-season team selection screen.

Slippery mode:
Press L1(2), R2, R1, L1, R2 at the pre-season team selection screen.

Turbo mode:
Press L1(2), Triangle(2), L1, Triangle at the pre-season team selection screen.