Here is the full list of all 9 What Remains of Edith Finch achievements. It takes around 2-3 hours to unlock all of the achievements on Windows.
Take both paths to the house
Knock all the letters of Gregory's name into the bathtub
Play Calvin's story again
Let the drunken sailor finish his song
Catch 2 rabbits with only 2 swoops
See Johann's name in the ending credits
Finish all stories
Look in all peepholes and telescopes long enough to hear Edith's commentary
Clear all balls off the pool table