Here is the full list of all 13 Empty Horizons achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Mireille reunites with Lyon.
Mireille heads out into the great unknown.
Mireille indulges herself, despite the shame.
Mireille braids Lyon's hair, as you do.
Mireille (finally) gets a choice.
Haven't you been here before?
Mireille recalls her first love.
Mireille ends her journey.
Mireille and Lyon bond.
Mireille gets her revenge.
Mireille ponders in the bathtub.
Mireille gets treated like a princess... for five seconds.
Mireille begins her journey.