Press L, Right, B, Down, L, R, Left, Start at the title screen.
Press Right, X, Down, Up, B, R, X, Start at the title screen. "Push Start Button" will turn red to confirm correct entry.
Now during gameplay, when there are no units on the map, hold L and R and press X to instantly win the map or A to instantly lose the map. Also, highlight a unit and press L and R to remove it.