Here is the full list of all 54 Last Light achievements.
Viewed all photos of the directors on the 1st floor.
Viewed all photos of the directors on the 2nd floor.
Viewed all photos of the directors on the 3rd floor.
Obtained Ralph's student ID.
Obtained Claudia's student ID.
Obtained Hunter's student ID.
Obtained Amelia's student ID.
Obtained May's student ID.
Obtained Morgan's student ID.
Obtained Lumi's student ID.
Used salt and a candle for the first time.
Used a key for the first time.
Ran into a wraith for the first time.
Ran into the Banshee for the first time.
Ran into a Fire Demon for the first time.
Died for the first time.
Sickened from drinking a beverage.
Died from drinking a beverage.
Refreshed from drinking a delicious beverage.
CHECKED a hidden door for the first time.
Obtained a surgical instrument for the first time.
Obtained a bloody doll for the first time.
CHECKED a dead body for the first time.
Opened a restroom stall door for the first time.
Experienced a door closing on its own.
Found the Bloody Locker.
Obtained the carrot diary.
Collected all of the wraith's diaries.
Collected all of the Banshee's diaries.
Collected all of the Fire Demon's diaries.
Collected all of the diaries of the hospitalized children.
Cleared the LIGHT mode.
Cleared the DIM mode.
Cleared the DARK mode.
Killed by Mask.
Killed by Louis.
Killed by Ellie.
Killed by Charley.
Killed by Leah.
Killed by AVa.
Died 10 times.
Found 50 items.
Placed 10 candles.
Placed salt 10 times.
Hid in a locker 10 times.
Managed to hide in a locker while wounded.
Tried to obtain an item while already having something in possession.
Encountered bloody hand prints for the first time
Relit the flashlight 10 times.
Opened all locked doors.
Obtained a bloodstained student ID.
Chose a Rabbit without a knife during the hide-and-seek event.
Met Rabbit for the first time.
Obtained a repair tool for the first time.