At the title screen, simultaneously press L1 and R1 and enter the following cheats:
Unlock All Characters: O, triangle, O, triangle, O, down
Unlock All Sleds: square, O, square, O, left
Unlock All Tracks: O, left, O, right, O, up
Unlock Everything: O, square, up, O, triangle, down
Unlock Hover Sled: O, triangle, square, O, triangle, right
Complete Championship Mode with any character to unlock the Rival Challenge option.
at the press start screnn: hold L1 + R1 and press the corresponding buttons:
CIRCLE, SQUARE, UP, CIRCLE, TRIANGLE, DOWN.
to get: EVERYTHING!
you know you want it
Complete Championship Mode with any character to unlock the Black Diamond course.
To unlock all characters, sleds and tracks, at the start screen hold [L1]+[R1], and press [Circle], [Square], [Up], [Circle], [Triangle], [Down] quickly.
Play Championship Mode and finish first in tracks which have the sled upgrade objective to obtain a new sled.