Full list of all 14 One Leaves achievements worth 1,000 gamerscore. It takes around 2-3 hours to unlock all of the achievements on Xbox One.
Found the Diseased Mouth
Made it to the Sewer Level
Discovered the Tarred Lungs
Found the Ex-Smoker
Found the Smokers Lounge
Opened All Four Drawers in the Morgue
Found the Hidden Flashlight
Found the Smokers Favorite Spot
Solved the Looping Hallway
Solved the Library Puzzle
Completed the First Interaction
Traverse the Maze 20 Times
Traverse the Maze and be Trapped
Traverse the Maze and Make It Out