Here is the full list of all 20 Ruya achievements.
Solved all puzzles in world one
Solved all puzzles in world two
Solved all puzzles in world three
Solved all puzzles in world four
Solved all puzzles in world five
Solved all puzzles in world six
Solved all puzzles in world seven
Solved all puzzles in world eight
Look carefully
Look within
Look around
Look up
Look patiently
Look for truth
Look for love
Look for home
They're musical
Picked a mushroom
She's shy
Solve every puzzle in the game