To unlock a Halloween version of Bart Simpson, set your Xbox's date to 10/31. Bart will appear as Frankenstein on the character select screen (under the ? category).

To unlock a special holiday outfit for Krusty, set your Xbox's internal clock to January 1. Krusty, in his spiffy duds, will be selectable from the Character Selection screen.

To see Apu dressed as Santa Claus, set your Xbox's date to December 25. The jolly Kwik-E Mart owner will then be available on the character select screen.

To see Marge all gussied up like a Pilgrim, set your Xbox's date to Thanksgiving day (November 22). Marge will be selectable at the character select screen.

Complete all 10 stages in Mission Mode to unlock a hidden car. You can pick this car in any mode by selecting Homer's picture at the car selection screen.

Change your split screen from vertical to horizontal, go to the Options screen, press and hold R & L, then enter the following code: Y, Y, Y, Y.

At the options screen, hold L and R, and then press B, B, Y, X.

Hold the left and right triggers then press B, B, X and A.

To unlock 2D Characters, go to the Options screen, press and hold R & L, then enter the following code: X, X, X, X.

To turn on Night Mode, go to the Options screen, press and hold R & L, then enter the following code: A, A, A, A.

To unlock Smithers, go to the Options screen, press and hold R & L, then enter the following code: B, B, Y, Y.

To unlock the Nuclear Bus, go to the Options screen, press and hold R & L, then enter the following code: B, B, Y, A.

To unlock extra camera views, go to the Options screen, press and hold R & L, then enter the following code: B, B, B, B.

To unlock Block Man, go to the Options screen, press and hold R & L, then enter the following code: B, B, Y, X.

For access to this cheats go to the Options
menu, hold the 'L' and 'R' triggers, then press:
B, B, A, A.