Here is the full list of all 15 Riddles of the Owls' Kingdom. Magic Wings achievements.
All levels with 3 stars
All Trophies collected
Fully restored Merlin's office
Collect all owls in Merlin's office
Hints used in 3 levels in a row
Solved level in less, then 120 seconds
"Crimson Field" world complete
100 levels with 3 stars
"Vaulted Caves" world complete
60 levels with 3 stars
"Old Library" world complete
40 levels with 3 stars
20 levels with 3 stars
"Garden in Bloom" world complete
Tutorial finished