At the "Press Start" screen, hold L1 + R1 and press Circle, Triangle, Circle, Triangle, Circle, Down.
All sleds
At the "Press Start" screen, hold L1 + R1 and press Circle, Square, Circle, Square, Circle, Left.
All tracks
At the "Press Start" screen, hold L1 + R1 and press Circle, Left, Circle, Right, Circle, Up.
Black Diamond Track
Using any character, win championship mode to unlock the Black Diamond track.
Cheat mode
At the "Press Start" screen, hold L1 + R1 and press Circle, Square, Up, Circle, Triangle, Down.
Easy Points for Secret Characters
Go to any track that you still need points to unlock a secret character. Find a large ramp and do a trick on it. Go back to the ramp and do it over and over again until you have enough points to get the secret character. Once you have enough, finish the race.
Hover sled
At the "Press Start" screen, hold L1 + R1 and press Circle, Triangle, Square, Circle, Triangle, Right.
Losing Sleds in Rival Challenge Mode
Make sure you don't challenge a rival that you can't beat. If you lose, you will also lose your sled and will have to unlock it again in championship mode.
Rival Challenge Mode
Using any character, complete the game in championship mode to unlock rival challenge mode.