Here is the full list of all 32 The Secret Order 8: Return to the Buried Kingdom achievements.
Find all Collectible items.
You hatched the egg of the new Mother Dragon.
You defeated the Dragon Rider.
You restored the sword.
You got inside the temple.
You healed Skaard.
Finish all Minigames without skipping.
You saved the Buried Kingdom.
You defeated the Skeleton Dragon.
Finish all Hidden Object Puzzles without any Hints.
Find all Morphing Objects.
You found the temple.
You revealed the dragon egg.
You freed Skaard from his box.
You removed the gem from Droi.
Finish five Hidden Object Puzzles without any Hints.
You entered Nezul's Tower.
You calmed the creature in Toadstool's hut.
You helped Dokka collect all the gems.
Finish ten Minigames without skipping.
You successfully got out of the cave.
Finish seven Minigames without skipping.
You've opened the tomb of Nezul.
Finish two Hidden Object Puzzles, each one with less than 10 mistakes.
Finish three Hidden Object Puzzles without any Hints.
You restored the Scorpion Staff.
You calmed Droi.
You found the secret passage.
Finish four Minigames, each one in 60 seconds without skipping.
You entered the Buried Kingdom.
Finish a Hidden Object Puzzle in 90 seconds.
Finish a Minigame in 60 seconds without skipping.