This game is also available on DS.
Retro Game Cheats for Mystical Ninja (Nintendo 64)
Effect: Option to face every boss in turn
When:
After the credits
How:
Complete the game after finding every cat
Submitted By:
Freeola
Effect: unlimited items and gold trick
When:
places where there is gold or an item
How:
Pick Them Up Then Come Back Into The Room And They Will Be There Again
Submitted By:
Unknown