In order to enter the codes below, you'll have to understand which medals are which. At the Password screen, you will see a line-up of four medals. Each of them starts out bronze, but can be manipulated to cause different effects. Each time you press down on the D-Pad, you will change the medal. The following is a list of medal names (in order) as you scroll down through the list:

Bronze
Cross
Valor
Silver
Honor
Bravery
Crown
Diam
ond