Unlock Mike Dias
At the main menu, press Up, Left, Down, Right, Right, Left, Up, Down, Up, Right, Square.

Unlock Amish Boy
At the main menu, press Up, Left, Down, Right, Right, Left. Left, Down, Up, Left, Square.

Unlock All Bikes
At the main menu, press Up, Left, Down, Right, Down, Down, Right, Down, Down, Left, Square