Begin your game and from the starting point, take three steps south and stand under gate's roof (your character's sprite will be out of view). Now, press Start to pause game and press Select to change the world's color to red. Next, press Down, A & B at the same time on the 2nd controller. Then unpause the game, enter the north door, talk to the girl in there and if you did it right, she will give you 100,000 gold.