Alternately, quickly press Up, Right, X, Square, Down, Left, Circle at the title screen. A sound will confirm correct code entry. Then, press R2 at the level map to remove all obstacles or R1 during game play to complete the level.
At the title screen, press triangle, up, square, right, X, down, circle, and left. You will then hear a a noise to confirm the code. Now start a game and when the map screen appears, press R2 to take out all the obstacles. During the game, press R1 to clear any stage.