Unlock some sweet secret riders with the codes listed below. All codes are entered when the game shows a 360-degree view of the garage and flashes the "Press Start" message. The hidden characters will appear alongside the other bikers in the garage.

Day Smith - B, Up, Down, Up, Down, Y
Volcano - B, Up, Up, A, Up, Up, A
Bigfoot - B, Right, Up, Right, Up, Y
Vanessa - B, Down, Left, Left, Down, Y
The Mime - B, Left, Right, Left, Right, Left