Enter Codes as Names in Tournament Mode :
The Word Cheater will appear to confirm correct entry.

All Tracks : WONITALL 
All Boarders : OPEN_EM
All Boards : GET_EM
Show Coordinates : SHOWPOS

Play as Alien & Snowman
Complete all 100 moves in master mode , then set all records in freestyle mode. Alternatively, achieve a score of at least 40.0 on the Half-pipe course.

Pervy Outfits
Highlight the Big Air option on the main menu and press: Down, R1, Up, R1, Down, R2, Up, R2, Up, Up, R1, Down, Down, R2. When you go to the character select menu (apart from in competition mode), Cindy will be wearing a skimpy leather outfit, while Irin dons a school uniform. You can change the outfits by pressing Cross, or using Left, and Right.

Play as The Boss
Complete Mirror mode in first place.

Bonus Boards
Enter freestyle mode with all the tracks. Set the top record for all the tracks.

Mirror Mode
Complete Snowboarding Combined mode and enter the options screen. Press Select on controller 2, then press R1 and Square, at the mode selection screen.