Here is the full list of all 18 Everybodys Gone to the Rapture achievements.
Completed the game
Triggered all of the story in the game
Spent time playing with Howard's train set
Read all of the Bittern books
Noted all of the train numbers
Made some tasty meals using the power of nuclear energy
Read all of the You Are Here maps
Spent time waiting for a call
Discovered the power of interactivity by doing nothing at all
Attempted to break into every caravan in Lakeside Holiday Camp
Arrived and left Wade's surgery many, many times
Simulated walking backwards for fifty seconds
Rode the Witches Hat for two minutes
Found all the Chads
Listened to all the radios before doing anything else
Used the hidden paths to return to each area in the game
Reached Stephen's bunker without ending any other story arc
Waited for a pint at The Stars and The Whistler