During gameplay pause the game and hold down the L Trigger and then press the following buttons to unlock the corresponding effect.

Unlock 10x Multiplier (Always special):
C-Down, C-Down, C-Down, C-Down, C-Left, C-Right, Right.

Unlock ALL Skater Stats at 13:
C-Down, C-Right, C-Right, C-Up, Up, Down, Right, Left.

Unlock Infinite Special Meter:
C-Left, C-Down, C-Up, Right, C-Right, Right.

Make ALL Skater Stats 10:
Down, Up, C-Up, C-Left, Down, Up, C-Up.

Unlock Moon Physics:
C-Down, C-Left, C-Right, C-Left, Up, C-Down, Down, Right, C-Down, C-Down.

Unlock Perfect Balance:
C-down, Right, Down, C-Left, C-Down, C-Up, C-Right, C-Left.

Unlock Simulation Mode:
Left, C-Right, Right, Down, C-Down, Up, Up.

Unlock Slow Motion:
C-up, Down, Left, C-Left, C-Down, C-Up, C-Right.

Unlock Slow-Nic Mode:
C-up, Down, Left, C-Left, C-Down, C-Up, C-Right.

Unlock Super Turbo Mode:
Down, Left, C-Up, C-Down, C-Left, Right, Up.

Unlock Thin Skater:
Left, C-Right, Right, Down, C-down, Up, Up.

Unlock Turbo Mode:
C-Left, C-Down, C-Up, Down, Up, Right.