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