Successfully complete the game under the Brutal difficulty setting. Then, enter any of the following codes at the title screen to activate the corresponding graphical filter.

Brutal mode filter color: Press Up(2), Down(2), Left, Right, Left, Right, X, Circle. Hard mode filter color: Press Up(2), Down(2), L1, R1, L1, R1, X, Circle. Normal mode filter color: Press Up(2), Down(2), Left, Right, Left, Right, Circle, X.

Filter	How to unlock