Here is the full list of all 16 Midnight Mysteries 3: Devil on the Mississippi achievements.
Complete a hidden object scene in less than a minute in Story mode.
Collect all the ravens in Story Mode.
Collect 100 clovers in Story Mode.
Find all the boats in Deptford without a miss.
Clear the pool table in one shot.
Find every hidden object in all Unlimited HO Mode scenes.
Complete the bonus chapter.
Find all of them 80 bones in "Dem Bones."
Complete each HOG in Story Mode without the lantern.
Complete Story Mode.
Solve all the puzzles in Story Mode.
Complete Story Mode without using any hints.
Complete Story Mode with no Black Cat scares.
Unlock Unlimited Hidden Object Mode.
Complete the Captain's lock puzzle.
Collect the skull from Joe.