Here is the full list of all 20 New York Mysteries: Secrets of the Mafia achievements.
Completed the main and bonus chapters without using hints in hidden object scenes.
Completed the main chapter on Hard mode.
Completed a hidden object scene without random clicks.
Completed the symbol plates mini-game without excess clicks.
Completed the main and bonus chapters without skipping mini-games.
Completed the main and bonus chapters without skipping dialogs or movies.
Completed the spot the difference mini-game without making a mistake.
Collected all the phantom objects.
Completed all collections.
Completed the casino chip collection.
Completed the tie collection.
Completed the statue of liberty collection.
Arranged the books showing the presidents' portraits in chronological order.
Found 3 items in 3 seconds in a hidden object scene.
Completed the briefcase collection.
Completed a trip in the underground city.
Completed a mini-game in more than 5 minutes.
Completed 3 mini-games in a row without using the Skip button.
Completed a mini-game in less than a minute.
Clicked more than three times in one second in a hidden object scene.