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.
Find and complete all collections.
Find all the miniatures.
Complete all the uniforms.
Find all the figurines.
Watch all Cutscenes without skipping.
Find five items in Hidden Object Puzzle in five seconds.
Finish a Hidden Object Scene without a mistap.
Solve three Minigames without skipping.
Solve three Minigames in less than ten minutes.
Finish a Hidden Object Puzzle without a hint.
Find three items in Hidden Object Puzzle in three seconds.
Solve a Minigame without using Skip.
Solve a Minigame in under a minute.