Ancient Ys Vanished: One Story in Two Games
Ys I ends on a cliffhanger because it was never meant to end at all.
The first two Ys games were originally intended as one game. Hashimoto and Miyazaki split the design into Ys I: Ancient Ys Vanished (1987), set in the land of Esteria, and Ys II: Ancient Ys Vanished – The Final Chapter (1988), which carries Adol to the floating land of Ys itself. The seam shows: Ys I concludes the moment its story opens up, and Ys II begins in the sky.
Between them they set every series constant: the six Books of Ys to recover, the goddesses Feena and Reah, the silver-haired villain Dark Fact, the faithful strongman Dogi, and health that regenerates while Adol stands still outdoors, a mercy borrowed from Hydlide and kept in nearly every Ys since.
THE TWO HALVES
Esteria, then the skyYs I: the omen
A compact game: one island, one tower. Darm Tower, twenty-five floors of it, is most of the map, and the climb through it remains the series' founding image of itself.
Ys II: the final chapter
Bigger in every direction: magic enters the combat, Adol can transform into a demon to talk with enemies, and the floating continent gives the series its name and its mythology in full.
Always together
Because the split was artificial, the two games have been bundled in nearly every era since, beginning with the 1989 PC Engine CD remake. Shops sell them as one item because, in every way that matters, they are one item.