Mystery Quest is a side-scrolling platform action game originally developed by Carry Lab, and published in Japan as Hao Kun no Fushigina Tabi (Hao Kun no Fushigina Tabi - literally Little Hao's Mysterious Journey) for the Famicom Disk System by Square in 1987. It was later localized for the American market and published for the NES by Taxan in 1989. While localizing the game, Taxan decided to make the game shorter and generally easier by eliminating over a third of the content. While Mystery Quest ends after only four castles, Hao Kun no Fushigina Tabi continues with a third world and two additional castles. Source: The Game Website.