Here are some cheats and tips for the game Bart’s Nightmare.
Level select:
Quickly press A, B(2), A, Down,
Up, Right(2), A while Bart is falling during
the opening sequence.
Control other characters:
Complete the game with at least 250,000 and earn an A+ rating.
Then, hold Start and press A, B, A,
C, B during the ending credits. Other Simpsons
characters will be selectable after the game restarts.