Shinobi is a side-scrolling action game starring Joe Musashi, a modern-day ninja sent to rescue hostages kidnapped by a criminal organization. The game is divided into five missions, each consisting of several stages and ending with a boss battle. In most stages, Joe must locate and rescue every hostage before he can proceed to the exit.
Joe attacks distant enemies by throwing shuriken, but automatically switches to punches, kicks, or other close-range attacks when an opponent approaches. Rescuing certain hostages grants a temporary weapon upgrade, replacing his shuriken with a firearm and strengthening his melee attack with a sword. He may also use a powerful ninjutsu technique once per stage, eliminating most ordinary enemies on the screen or inflicting heavy damage on a boss. Completing stages without using ninjutsu, or under other special conditions, can award additional bonus points.
Enemies include gunmen, sword-throwing guards, martial artists, and rival ninjas with different weapons and attack patterns. Many stages contain upper and lower routes, between which Joe can leap to avoid obstacles, reach hostages, or gain a better position against enemies. The final stage of each mission replaces the usual hostage-rescue objective with a confrontation against a large boss, including an armored warrior, an attack helicopter, and other unusual opponents.
After each of the first four missions, the arcade version presents a first-person bonus round. From behind Joe’s hands, the player must throw shuriken at waves of ninjas before they advance close enough to attack.
The home conversions vary considerably in their fidelity to the arcade game. Some alter the stages, enemies, controls, weapon upgrades, or ninjutsu system, while others add a health meter or omit features such as the bonus rounds. The Master System and NES versions make particularly extensive changes to the original design. The Wii and Xbox 360 releases emulate the arcade version, while the Nintendo Switch SEGA AGES edition adds features including rewind, a dedicated close-range attack button, display options, and an alternate mode in which Joe begins with upgraded weapons and can withstand additional hits.
