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
A trait passed on
Together forever
She is watching
Use it well
Dark turned to light
Release it
The guardian
Where they roam
Free at last
Grow more
Fruit from the tree
A magic gift
Being friendly
Friendship
Water or not
They are precious