Let me just go straight to the point. This code only works for Ken-Ta, Ash, J and Keith. If you have a "S" class, after the replay the guys will do a different pose than novice mode.Like for example, Ken-Ta breakdances than do a "round da' world", with his yo-yo.
Super Deformed Mode
At the stage select screen, press the left select button nine times, right four times and left five times. Next lean the board forward (step on the front of the board) and press both the left and the right select buttons simultaneously three times. When you get to the character select screen each character should appear in super-deformed mode.
Auto S-Class Trick
When in a half pipe, head as far vertical up as you can. before reaching the top, hit the back or front of the board down 2 times. You should get an automatic S-class trick.
Big Head Mode
At the Course Select screen, press Left 9 times, Right 9 times, Right 4 times, Left 4 times, Right 5 times, and Left 5 times. Next, lean forward on the board and (while holding forward), press Left and Right together 3 times. If you do this correctly, you will hear a laughing sound.
To perform a continuous grind, hold down the front or back end of the board on the grinding pole.
To access the secret, freestyle course, do the following:
At the course select screen, lean and hold FORWARD on the board, then press RIGHT to highlight the expert course. While continuing to hold forward, press the START button and choose your character. Continue to hold the board down until you feel click and the screen says "ACTION BOARD WILL UNLOCK."
As you approach the "BIG AIR" jump at the beginning of the course, DO NOT MAKE A JUMP. Simply "fall off" the edge without leaning backwards or forward to make a jump. At the beginning of the arena on the left side there is a broken fence. Jump into the area to warp to the secret course.
Enjoy the freestyle course, you have 90 seconds, there are no time bonuses or checkpoints.
To change the stance of the players from normal to goofy and vice-versa, press Left and Right together on the character of your choice (at the character select screen.) This trick does not work on P-Nut, and it will make Alex "surf" backwards).
Grinding Made Easy
When coming up to a grind rail, kick the nose of your board (instead of your tail) when right in front of the rail. If done correctly, you will get on, doing a 50-50, 5.0, nose slide, tail slide, blunt slide, boardslide, K- Grind, or crooked grind.
Play as Alex the Surfer
At the Skater Select screen, press Left 3 times, Right 3 times, then press Left 14 times before the counter reaches 0. If you were quick enough you'll see Alex.
Play as P-Nut
At the Course Select screen, press and hold Start (don't release it!) At the Character Select screen, press Right 6 times, Left 6 times, Right 3 times, Left 3 times, and Right 4 times. You should now be Cookie. Release Start and Cookie will be wearing a swimsuit and a boogieboard.