Pause the game and Hold L. Then, press Right, Down, Right, Left, Right, Up, Right, Right.

Unlock Tiki Man

Pause the game and press Left, Down, Up, Left, Right, Up, Down, Left.

Unlock Norton

Pause the game and press Left, Right, Up, X, Y, X, Up, Right.

Unlock Brittany

Pause the game and press Right, Left, Right, Right, Left, Right (3x).

Unlock Tito

Pause the game and press Down, Up, Right, Down, Up, Left, Down, Up.