Here is the full list of all 12 Nancy Drew: the Ghost of Thornton Hall achievements.
For being a bottle botherer.
You know your way around a teacup.
You're a gin genie!
You're hip to all Thornton family secrets!
Just because.
For leaving no ghost unturned.
You're quite a grave individual.
Everyone lives!
At this point, we think that you just like doing stuff a lot.
No spoilers for you! HEROIC!
For bravely looking at ghosts!
For trivia excellence.