Enter the following codes as cheats. Directions such as LEFT and RIGHT refer to the arrows you can enter.

Level select, all park editor objects, full stats - UP, UP, DOWN, DOWN, LEFT, RIGHT, LEFT, RIGHT, B, A, B, A
All bonus characters - DOWN, RIGHT, RIGHT, DOWN, LEFT, DOWN, LEFT, DOWN, RIGHT, RIGHT, RIGHT
Low gravity wallride - UP, DOWN, UP, DOWN, LEFT, RIGHT, LEFT, RIGHT, A, B, A, B, S
Juice regeneration - LEFT, LEFT, RIGHT, RIGHT, LEFT, RIGHT, DOWN, UP, UP, DOWN, A
Juice bar is always full - B, A, K, A, B, A, K, A
Juice remains after crashes - K, H, U, F, U
FMV sequences - complete all normal challenges in any level to unlock that level's FMV sequence.
Power Skates - Complete all normal and hidden challenges on every the level.
Ultra Skates - Complete all the levels with 100%.
Snowmen decorations - Automatic when the PlayStation 2 console's system clock and date is set for any day in December.