The Incredibles (Game Boy Advance)

Level Select
In the password screen, enter either SNDF or MSMC. The game will return to the main menu, and you'll see a box with some numbers at the bottom of the screen corresponding to level numbers. Press L or R to change its value (note that the values with "B" and random numbers and letters are the bosses) and select a stage, then select "New Game" to go directly to that stage. You'll also be able to view the startup legal screen and the credits, as well as view the title screen (which seems somewhat pointless...).