Unlimited lives:
Press Up, Down, Left, Right, Up, Down, Left, Right, P at the title screen. A brief tone will confirm correct code entry.
View all FMV sequences:
Start a game and allow Dexter to lose all five lives. Press Right(2), Left(2), Down(2), Up(2), P at the continue screen, A brief tone will confirm correct code entry. The game will restart and show all losing and winning scenes.