Moon Gravity:
At the main menu, Press Up, Up, Up, Up, R1, Square, Circle. If entered properly, the lower left corner of the screen will flash. 

Unlimited Turbo:
At the main menu, press R2, L1, Square, Circle, Circle, Circle. If entered properly, the lower left corner of the screen will flash. 

Unlock All Bikes: 
Complete the hardcore part of career mode.
 
Moves List:
Cliffhanger: Hold L2 + R2 and press Left, Right, Up.
Crack-Nac (Left): Hold L2 + R2 and press Down, Left.
Crack-Nac (Right): Hold L2 + R2 and press Down, Right.
Heart Attack: Hold L2 + R2 and press Left, Up, Down.
Indian Air: Hold L2 + R2 and press Left, Down.
No Hands: Hold L2 + R2 and press Up, Down.
Nothing: Hold L2 + R2 and press Down, Up.
Switchblade (Left): Hold L2 + R2 and press Right, Left, Left.
Switchblade (Right): Hold L2 + R2 and press Left, Right, Right.