Star Arthur Densetsu I: Wakusei Mephius (Legend of Star Arthur I: Planet Mephius) was authored by Eiji Yokoyama and published by T&E Soft for the FM-7 computer in July 1983. It was one of the earliest adventure games to use a command menu system. Its key innovation was the introduction of a point-and-click interface, utilizing a cursor to interact with objects on the screen. It was the first adventure game to support a mouse. Along with these innovations, it still supported the traditional text-parser input used by other adventure games at the time.
The PC-6001 port also featured another innovation for adventure games: speech synthesis. This allowed dialogues in the game to be voiced using speech synthesis.
In addition, it was the first episodic adventure game, as the first part of the Legend of Star Arthur trilogy, followed by sequel Star Arthur Densetsu II: Ankoku Seiun (Legend of Star Arthur II: Dark Nebula) in December 1983 and Star Arthur Densetsu III: Terra 4001 (Legend of Star Arthur III: Terra 4001) in December 1984.
The MSX version was one of the first computer games with FMV backgrounds & cutscenes, featuring laserdisc anime footage both for storytelling cutscenes and for background graphics overlayed with real-time graphics (the point & click cursor and text-parser interface).
The plot is an epic, futuristic, sci-fi space opera adaptation of the King Arthur legend, along with elements of Dune. Set in the year 3826, the Galactic Federation is at war with the galactic fleet of Jamil. As the war wages on, Star Arthur travels to Planet Mephius in search of a legendary sword...