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.
Find all the miniatures.
Find and complete all collections.
Complete all the uniforms.
Destroy the Spear.
Solve all the Minigames without using Skip.
Finish all Hidden Object Puzzle without using Hint.
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.
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.