Kenseiden

Kenseiden is a 1988 action-platformer developed and published by Sega for the Master System, known in Japan as Sword Saint Legend. Often described as a feudal-Japanese take on Castlevania, it follows the samurai Hayato Kagemori on a quest to defeat the Book of Necromancy and its monstrous guardians.

Rather than a single linear path, players pick provinces to tackle from a map of Japan and learn new sword techniques along the way, gating access to tougher regions — an early, distinctly Japanese entry in the Metroidvania lineage.