Saigo no Nindou (最後の忍道), the Game Boy adaptation of Irem's arcade classic better known in the West as Ninja Spirit. Take control of the ninja Tsukikage in a fast, atmospheric side-scrolling action platformer.
Story: A lone ninja sets out on a quest for vengeance, cutting through hordes of enemies and supernatural foes across feudal Japan.
Gameplay: Run, leap and slash your way through multiple stages, switching between several weapons (sword, kunai/shuriken, bombs and the kusarigama) as you fight waves of soldiers, demons and towering bosses. A signature feature is the ability to summon spirit doppelgangers that mirror your attacks, doubling your firepower against the relentless onslaught.
This is a Japanese-language cartridge (text is minimal and in Japanese). Developed by BITS and published by Irem in 1993.