Enter these at the title screen. Lisa's treasures:XYXXY then the left d-pad. Lisa's outfits:XYXXY then the left thumbstick in. Bart's outfits:D-pad right D-pad left XXY Right thumbstick in. Marge's outfits:YXYYX Right thumbstick in. Homer's outfits:D-pad left D-pad right YYX left thumbstick in.
Enter the following codes at the 'Main' menu to unlock ALL of the indicated characters costumes and trophies. If you enter the code correctly you will hear Bart laugh as confirmation. The code will remain enabled only during the current game.
Unlock Bart's Costumes and Trophies: Press Right, Left, X(2), Y, click the Right analog-stick.
Unlock Homer's Costumes and Trophies: Press Left, Right, Y(2), X, click the Left analog-stick.
Unlock Lisa's costumes and Trophies: Press X, Y, X(2), Y, click the Left analog-stick.
Unlock Marge's Costumes and Trophies: Press Y, X, Y(2), X, click the Right analog-stick.