Here is the full list of all 10 Degrees of Separation achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Find the hidden room in the Castle
Collected all scarves in the second world
Collected all scarves in all worlds
Collected all scarves in the third world
Collected all scarves in the first world
Collected all scarves in the Castle
Jump into the abyss in the Castle
Collected all scarves in the fifth world
Collected all scarves in the fourth world
Find the secret attic in the Castle