At the main menu press Down, R1, Left, Right, Down, L2, R2, Left, Right, Up.
At the main menu press Up, Left, Down, Left, Down, L1, R1, Right, Down, Right, then start a new game.
At the main menu press Right, L1, Up, Right, Down, L1, R1, Up, Down, Left.
At the main menu press Up, L1, Down, Up, Left, R1, L2, Down, Left, Right.
At the main menu press Left, R1, Right, Up, Down, R2, L1, Right, Up, Down.
Press left, down, right, left, up, R2, L1, up, left, right at title screen.