Here is the full list of all 16 Agent Walker: Secret Journey achievements. It takes around 3-4 hours to unlock all of the achievements on Windows.
Destroy the Spear.
Solve all the Minigames without using Skip.
Finish all Hidden Object Puzzle without using Hint.
Watch all Cutscenes without skipping.
Finish a Hidden Object Scene without a mistap.
Find three items in Hidden Object Puzzle in three seconds.
Solve three Minigames in less than ten minutes.
Solve three Minigames without skipping.
Finish a Hidden Object Puzzle without a hint.
Solve a Minigame without using Skip.
Solve a Minigame in under a minute.
Find five items in Hidden Object Puzzle in five seconds.
Complete all the uniforms.
Find all the miniatures.
Find all the figurines.
Find and complete all collections.