All Things Nintendo:N64 Codes:Mystical Ninja Starring Goemon

Mystical Ninja Starring Goemon
Big Boss Fighting Mode
To access the Consecutive Fighting Large Boss Mode, first get all of the 45 Fortune Dolls and then beat the game. After you do this a new option will appear in the options menu allowing you to fight all of the Goemon Impact bosses in consecutive order.
Credit Goes To: Robert Slack ( via N64cc

 Big Boss Fight Mode
 Ninjitsu 360 Blade

 Hidden Store
Ninjitsu 360 Blade Slash
Rapidly rotate the control stick in a 360 motion while rapidly taping the B button. This produces a Ninjitsu 360 Blade Slash that will kill all the enemies around you.
Credit Goes To: Jaime Wilkins via N64cc

Hidden Store
First you must have Yae's mermaid power, which you get by passing the Waterfall of Kegon challenge in Uzen Tunnel. Then go back to Festival Village. Go to its main shopping district (the one with the pond) and switch to Yae. Jump in the pond and press C-Up to activate her power. Now look for an underwater tunnel in the pond. Swim through it to reach another area. There is a special store where you can buy Gold Helmets (250 ryo), Gold Armor (350 ryo) and extra lives (500 ryo).
Credit Goes To: Max Bitter ( via N64cc