Duke Nukem (GBC)

Invincibility:
Press Up, Down, Down, Left, Right, Left, Up, Up at the title screen.


Level Select:
Press Left, Right, Up, Up, Down, Up, Right, Left at the title screen.


Avoid falling damage:
(submitted by: _IMP_ [TML])
If you fall a great distance then pause and then un-pause just before you
hit the ground to stop yourself from recieving damage.