Full list of all 24 Outlast 2 achievements worth 1,000 gamerscore. It takes around 40-50 hours to unlock all of the achievements on Xbox One.
Finished the game in Insane Mode
Finished the game in Insane Mode without reloading the camera battery
Finished the game in under 4 hours
Spent 10 minutes underwater
Finished the game in Nightmare Mode
Crawled for 500 meters
Collected all documents
Used the microphone for 20 minutes
Completed all recordings
Collected 40 documents
Finished the game in Hard Mode
Finished the game without hiding in a barrel or closet
Performed a twelve-meter blood slide
Finished the game
Witnessed the end
Reunited with Lynn
Descended into the mines
Reached the mine facility
Completed 30 recordings
Escaped from the Scalled
Used 10 bandages
Escaped the crucifixion
Saw the distant mines where Lynn was taken
Found Lynn