Ys: The Vanished Omens (also referred to as Ys 1: Ancient Ys Vanished and The Ancient Land of Ys) is the first game in Falcom's long-running Ys series. As with almost every subsequent game, the player controls a quiet but steadfast redheaded swordsman named Adol Christin as he fights to uncover an ancient mystery and defeat the evil entity behind it all.
Ys is notable for being one of the earliest story-driven Japanese RPGs, providing many NPCs for Adol to talk to and a constant string of goals and side-quests to follow that tie directly in with the narrative. This is opposed to the previously standard system, which left players to simply explore dungeons at their own pace with usually nothing more than an introductory text crawl and a nebulously evil final boss to head towards. The game's forgiving action-RPG gameplay, which included regenerating health among a number of other features, made it more accessible than most computer RPGs at the time.
Ys was originally created for the NEC PC-8801 home computer, but was later ported to many other home computers in Japan, mostly unedited. It also received several console versions. Each was significant in its own way: Victor Musical Industries published Nintendo Famicom version was greatly modified from the original PC-8801 version, in terms of dungeon layouts, graphics and enemy encounters; the NEC Turbografx-16 version would later be adapted into a two-part compilation with its sequel Ys II for the system's CD-based upgrade, complete with additional anime cutscenes; and the Sega Master System version is one of the few to be translated into English and released in the US. There were also Apple-II and DOS home computer versions for US gamers.
The Turbografx-CD compilation Ys I & II (often known as Ys Books I & II) would also be released a few more times with additional features and graphical improvements, first as an updated version for PC in 2001 called Ys I & II Complete and eventually for the PS2, DS (Legacy of Ys: Books I & II) and PSP (Ys I & II Chronicles). A second PC version was released in 2007. With the exception of the DS and PSP versions, these remakes were all Japan-only.