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