Alex Kidd's basic attack is a sword slice, which can be used not only to destroy enemies but also to open treasure chests.

Inside such chests, the player can obtain items such as more health, throwing darts, a powered-up sword, extra lives, and a magic ball that will temporarily turn Alex Kidd into an invincible tornado.

Other actions that Alex Kidd can perform include a wall-to-wall jump and the ability to turn into a flying fireball after spinning around a street post, a rope or a horizontal bar.

An evil being known as Hanzo the Dark Ninja escapes after 10,000 years of confinement and kidnaps Alex Kidd's new girlfriend, while the pair are on a leisurely trip to the planet Shinobi.

Mari-Oh shares two qualities with his Nintendo namesake: he attacks the player by shooting bouncing fireballs and after sustaining enough damage, he shrinks to a smaller size.

Although Mari-Oh was renamed Kabuto in the finished, with a redesign that downplayed his likeness to Mario, his attack pattern remained unchanged from the prototype.