Tenchu - Stealth Assassins

Tenchu: Stealth Assassins put players in the sandals of a feudal Japanese ninja years before stealth mechanics became a genre staple, rewarding patience over confrontation with a grappling hook, a stealth kill from directly behind an enemy, and a detection system built around light and sound rather than a simple vision cone. Levels can largely be cleared without ever being seen, and a single sword strike from an alerted guard can end a run, making careful observation the core skill rather than combat reflexes.