Use the following codes at the main screen before the pick player screen to unlock the corresponding effect:
Get Expert Mode: Circle, Square, Circle, Circle, Square, Start
Get Atomic Snowball Mode: Square, Square, Square, L1, Circle, Start
Get Rooster Tails Mode: R1, R2, l2, L1, Square, Start
Get No Drones Mode: Square, Square, Circle, Circle, L1, R1, Start
Get Random Mode: R1, R2, Square, Circle, R1, R2, Start
Get Random & Grappling Hooks Mode: Circle, Circle, L2, Circle, Circle, L1, Start
Get All Boost Mode: Circle, R1, R1, Circle, R2, Start
Get Random & Snow Bomb Mode: Circle, Circle, R1, R2, Start
Make Everyone Invisible: Square, Circle, Square, R2, Circle, Circle, Start
Get Super boost Wheelie: Circle, L1, Square, R2, Square, L2, Start
Get Clone Mode: L1, L2, L2, Circle, L1, Circle, Start
No Power Ups: Square, Square, Circle, Square, R2, Square, Start