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.
Complete the First Interaction
Solve the Looping Hallway
Find the Smokers Favorite Spot
Solve the Library Puzzle
Find the Hidden Flashlight
Find the Smokers Lounge
Discover the Tarred Lungs
Find the Ex-Smoker
Open All Four Drawers in the Morgue
Make it to the Sewer Level
Find the Diseased Mouth
Traverse the Maze 20 Times
Traverse the Maze and be Trapped
Traverse the Maze and Make It Out