Batman Returns
Contributed by - Richard

Extra lives:
Highlight the "Rest" selection on the options screen, then press Up,
Up, Down, Down, Left, Right, Left, Right, B, A, B, A on controller
two. A tone will confirm correct code entry. Up to ten lives may now
be selected on the options screen. 

Invincibility:
Press Up(8) at the title screen. 

Nine continues:
Highlight the "Rest" selection on the options screen, then press Up,
X, Left, Y, Down, B, Right, A, Up, X on controller two. A tone will
confirm correct code entry.