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