Varius Codes
-On the Title Screen press select and a simultaneously. Release
them and press select and b simultaneously. Repeat this process
until you hear a ding. Start game.  While playing, hold down
select and press:

Right       Temporary Invincibility         
Left        Add gold
Up          Super Jump                         
Down        Restore life meter
Up/Right    Add lives        
Down/Left   Power Up Sword
Up/Left     The Fire Weapon                

Sound test
-At the title screen hold A/B and hit Select