Here is the full list of all 16 Midnight Mysteries 4: Haunted Houdini achievements.
Find every hidden object in all Unlimited HO Mode scenes.
Complete a hidden object scene in less than a minute.
Find all 100 padlocks, handcuffs, keys and straightjackets in "Escape Artist Hunt."
Complete the bonus chapter.
Complete each HOG in Story Mode without the lantern.
Solve all the puzzles in Story Mode.
Complete Story Mode.
Complete Story Mode without using any hints.
Complete Story Mode with no Black Cat scares.
Collect all 70 clovers in Story Mode.
Collect all 52 ravens in Story Mode.
Escape from Houdini's coffin in one try.
Unlock Unlimited Hidden Object Mode.
Find all the ESP cards in the garden in one try.
Conjure a pigeon.
Get into Houdini's house without a hint.