Alex Kidd in Shinobi World

Alex Kidd in Shinobi World is a platformer developed by Sega for the Master System in 1990.

Plot
After 10,000 years Hanzo, the dark ninja, has returned from his banishment. Finding his powers drained, he decides he needs to perform a ritual to restore himself to his former glory.

Alex Kidd, meanwhile was standing in a flower field with his girlfriend when Hanzo appeared from nowhere, snatched her and disappeared. Distraught and stunned afterwards, Alex was unsure how to save her until the White Ninja 's spirit appeared before him.

The White Ninja reveals he was the one who defeated and banished Hanzo all those years ago.

Fusing with Alex, he bestows upon him his ninja powers and knowledge in order to let Alex rescue his girlfriend, prevent the ritual from happening and put a final end to Hanzo.

Gameplay
As the title suggests, Alex Kidd is essentially thrust into the hero's role in a Shinobi game.

Alex Kidd's abilities in this game are different from his other games as a result, besides jumping. Alex now swings a sword rather than punching, can throw kunai upon getting a power up, can spin around lamposts to turn himself into a spinning fireball capable of smashing through enemies and blocks and can even use ninja magic to transform himself into a spinning tornado.

Alex Kidd in Shinobi World contains four worlds known as 'Round's:


 * Round 1: Kabuto (Boss: Kabuto)
 * Round 2: Raid of the Helicopters (Boss: Heli)
 * Round 3: The Jungle (Boss: Robster)
 * Round 4: The Battle with the Dark Ninja (Boss: Hanzo)

=Shinobi Kid (original / working title)= In 2007, images and articles began to surface on the internet, that like Alex Kidd: High-Tech World, Alex Kidd was not originally intended to be the star of the game. Rather, the game was initially devised to be a cute parody of Shinobi, in a similar vein to Kid Dracula was to Castlevania, Splatterhouse: Wanpaku Graffiti was to Splatterhouse and Parodius was to Gradius.

Trivia

 * Kabuto, the first boss was originally designed to look exactly like Nintendo's Mario in samurai gear, even unsubtly being called Mari-Oh until being changed to avoid copyright issues. He is also based off Ken-Oh, the first boss from Shinobi.
 * Heli, the second boss(or bosses as it's many small helicopters) seem to be modelled after Opa-Opa. They are based off the Shinobi boss Black Turtle who fought Joe Musashi in an attack helicoptor.
 * Robster, the third boss is based off the Shinobi boss Lobster, a samurai in red armour. Amusingly, Robster is an actual lobster, who upon defeat fries himself with butter.
 * Hanzo, the final boss of the game is based off the Masked Ninja final boss from Revenge of Shinobi. Hanzo wears a Hyottoko Mask, known for being a childish and comical character. When the mask is broken off his face, it's revealed Hanzo's face looks exactly the same underneath.
 * Despite its Japanese feel and origin, Sega never released Alex Kidd in Shinobi World in Japan. This is the only Alex Kidd title to not be released in Japan, although High-Tech World wasn't originally an Alex Kidd title.
 * Alex's Girlfriend from this game appears in the SEGA AGES art work as a scorecard girl. She's unlockable in SEGA AGES: Columns 2's Jewel case.
 * This was the last game in the Alex Kidd series until 2021's Alex Kidd in Miracle World DX.