Initially developed for the PC-8801, PC-9801, FM-7, X1, and MSX2 Japanese systems, Ancient Ys Vanished saw many subsequent releases, such as English-language versions for the Master System, DOS, IIGS, and TurboGrafx-16, and enhanced remakes for the Saturn and Windows systems. It is also slated to be released for the Nintendo DS.
Adol is informed that he must seek out the six Books of Ys. These books contain the history of the ancient land of Ys, and will give him the knowledge he needs to defeat the evil forces. Sara gives Adol a crystal for identification and instructs him to find her aunt in Zepik Village, who holds the key to retrieving one of the Books. With that, his quest begins.
Combat in Ys I is rather different from other console RPGs of the time, where battles were often turn-based and menu-oriented. Ys I rather featured a battle system quite similar to that of typical roguelike. The protagonist simply moves into his enemy and damage is sustained on both sides. Attacking straight on causes the attacker the most damage to himself; it's clipping the edge of the defender that yields a successful differential.
The most distinctive of the early ports was the Famicom edition, which was developed by Victor Musical Industries. This version was a vast departure from the original, featuring entirely new layouts for the towns, field, and dungeons, replacement of a number of the original musical tracks, and a new final battle sequence.
The version developed for the MSX contained a handful of new musical tracks which replaced part of the original game's soundtrack. Some of these tracks, along with a number of unused tracks first composed for the original, were later incorporated into the soundtrack of Ys Eternal and Ys Complete.
The versions developed for the PC Engine CD-ROM² and Sega Saturn included additional cutscenes, such as an opening detailing Adol's arrival in the town of Minea. The Microsoft Windows-based remakes, Ys Eternal and Ys Complete, expand further on this and many other story elements, through both cutscenes and additional gameplay.
Several soundtrack albums dedicated to the music of Ys I have been released by Falcom. These include: