Here is the full list of all 18 Hermitage: Strange Case Files achievements.
Reached the final ending in no more than 5 ponderings
Watched all the TV programs in game
Browsed all the forum posts in game
Successfully completed the final ending
Successfully completed Chapter 5
Reached the bad ending of Chapter 5
Reached the bad endings of all chapters
Unlocked all the intelligence pieces in game
Successfully completed Chapter 4
Unveiled all secrets of the abandoned factory
Reached the bad ending of Chapter 4
Successfully completed Chapter 3
Reached the bad ending of Chapter 3
Successfully completed Chapter 2
Reached the bad ending of Chapter 2
Successfully completed Chapter 1
Reached the bad ending of Chapter 1
Completed the first deduction