Full pause screen:
Pause game play, then press X + Y. 

Alternate clothing:
Successfully complete the game with any character to unlock an additional set of
clothing for that character. 

All tracks:
Select two player mode and begin game play. Quit the game, select free ride mode,
complete the first course, then quit the game. Return to two player mode and begin
game play. The "Next Course" option will be available after each race including
access to the special track after the credit track. 

Cool Boarders 2 practice track:
Successfully complete all five standard tracks (Mountain Review, Emerald Forest,
Urban Striker, Cave Slider, and Dancing Devils). 

Secret Force track:
Successfully complete all five standard tracks with the high score. 

Longer super pipe:
Break various records in the super pipe. 

Play as Snowman:
Successfully complete the Cool Boarders 2 practice track with the high score. 

Play as Gray:
Successfully complete the Secret Force track. 

Hidden snowboards:
Get the top score for each track to unlock new snowboards. There are a total of over
forty snowboards in the game.