Here is the full list of all 20 Star Sky 3 achievements.
They Meet at Last
Path to the Waking World
It is uncovered
A beautiful thing
Together forever
Use it well
Dark turned to light
Release it
She is watching
The guardian
Being friendly
Grow more
Water or not
A trait passed on
A magic gift
Where they roam
Free at last
They are precious
Friendship
Fruit from the tree