Alex Kidd in the Enchanted Castle is a side-scrolling platform game developed and published by Sega for the Sega Genesis video game console. The story continues that of Alex Kidd in Miracle World (1986). Alex lives on Planet Aries which is ruled by his brother, King Igul. After hearing a rumor that his long-lost father, King Thor, is still alive on Planet Paperock, Alex travels to the planet to search for him.

The player guides Alex through eleven stages by fighting and avoiding enemies and obstacles. Alex can jump, kick, crawl or punch enemies, causing them to explode into gold coins, called Baums. New items and vehicles are gained by playing Janken (Rock, Paper, Scissors) in gambling houses, including the Sukopako Motorcycle, the pedicopter (a small pedal-powered helicopter), a pogo stick and wizard cane which allows Alex to float in the air for a few seconds. One hit from any enemy causes Alex to die instantly.