VGFacts

If your console or PC's internal clock is set to either October 31st, the last Thursday of November or December 25th, whilst playing the Simpsons: Hit & Run the main menu will feature either a Halloween, Thanksgiving or Christmas theme on those respective dates.

Halloween


Thanksgiving


Christmas

I remember a teenage mutant ninja turtle game on the gamecube that did the same thing but with character models. Don't know what it was if there are more than 1.