A short (2 hours-ish) but very nice graphical adventure. Chapter-select after completing the game will let you replay to pick up any achievements you missed.
Difficulty does NOT affect achievements
Steam achievements do NOT work offline
7 missable achievements (plus 2 unknown)
Sign in with Steam or Xbox to track your progress, and:
Finish all stories
See Johann's name in the ending credits
Take both paths to the house
At the beginning of the game when walking to the house, there is a fork a short way in, with a small path down to the left in the trees. Take one path all the way to the bridge where you can see the house - then go back and take the other path.
If you take the left fork (down the slope into the trees), and come back on the main path, the achievement should unlock around halfway back - this is likely the quickest way,
Knock all the letters of Gregory's name into the bathtub
Catch 2 rabbits with only 2 swoops
In the first story, while you are an owl. If you miss on one of the attempts, use Chapter Select after completing the game.
Look in all peepholes and telescopes long enough to hear Edith's commentary
These are listed in the order you will get to them as you go through the game.
Sign in to track your progress against these checklist items
Play Calvin's story again
You can replay any story after completing the game. Replay Calvin's (to the end of his story)...
Clear all balls off the pool table
Let the drunken sailor finish his song
In the first story, on the ship, there will be drunken sailor singing to himself. Get close enough to listen, but no closer, and wait a few minutes until he finishes before carrying on.