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