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