The Pirates of Dark Water

Play as same character in two player mode:
Quickly press Up, Down, Y, B, L, Left, Right, X, A, R when "Press Start" flashes on the title screen.

View ending sequence:
Press R, A, L, A, R(2), L(2), R, A when the "1P Mode", "2P Mode", and "Options" menu appears at the title screen.