Here is the full list of all 36 The Invisible Hours achievements.
Find all the newspapers clips
Go to the hotel room
Use the Spirit Radio
Listen to the lullaby
Discover who killed Tesla
Travel back in time with Flora
Watch all the scenes in chapter 4
Find all of Tesla's diaries
Find all the letters from the guests
Collect all the clues
Watch Mundy's death
Watch Gustav's fall
Watch Gustav for the entire game
Watch Vanderberg's murder
Watch all the scenes in chapter 3
Watch all the scenes in chapter 2
Watch Bernhardt and Mundy recite Shakespeare
Watch Bernhardt putting on makeup
Watch all the scenes in chapter 1
Watch Edison play chess
Find old photos of all the characters
Explore the entire Island
Find the secret workshop in the basement
Find the library receipt
Find the fox
Find Deadlight logo
Look through the telescope
Find the chemistry notes
Find the Ulysses poem
Find Lafcadio Boone's mask
Try to bang the gong
Find Edison's food bowl
Find the first Tesla Diary
Find the hats
Activate Following mode
Be walked through by a character