To unlock all of Bart's trophies and outfits, head to the game's main menu and insert the following password: Right, Left, X, X, Y, Right Thumb Stick (push in).
To unlock all Homer-related costumes and trophies, insert the following code while browsing the main menu: Left, Right, Y, Y, X, left analog stick (press).
To unlock all Lisa-related costumes and trophies, insert the following code while browsing the main menu: X, Y, X, X, Y, left analog stick (press).
To unlock all of Marge's outfits and trophies, head to the main menu and insert the following password: Y, X, Y, Y, X, Right Thumbstick (press in).