Here is the full list of all 16 Skyland: Heart of the Mountain achievements.
Finish the final Fight Puzzle without using Skip.
Finish Bal's Diary Puzzle without using Skip.
Extinguish all the fires.
Find half of the Collectibles.
Save the seer.
Finish 3 Hidden Object Puzzles without using hint.
Finish a Hidden Object Puzzle with less than 3 mistakes.
Complete 3 Minigames without a Skip.
Finish a Puzzle in less than 30 seconds.
Finish a Fight Puzzle without using Skip.
Win the fight against the first drone.
Find the first Collectible.
Seek those who climb high.
Finish a Hidden Object Puzzle in less than 20 seconds.
Finish all the Hidden Object Puzzles without using Hint.
Find all the Collectibles.