Here is the full list of all 37 Salt and Sanctuary achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Take an oath to The Iron Ones.
Bear all possible brands.
Discover your first brand.
Achieve the maximum devotion level in your creed.
Defeat the Kraekan Cyclops.
Defeat the Mad Alchemist.
Defeat the Queen of Smiles.
Take an oath to The Three.
Defeat the Sodden Knight.
Claim your first sanctuary.
Take an oath to Devara's Light.
Defeat the Unspeakable Deep.
Aid a despondent thief.
Aid a questing knight.
Aid an unraveling sorceror.
Take an oath to The Stone Roots.
Take an oath to the gods of Fire and Sky.
Take an oath to The House of Splendor.
Take an oath to the Order of the Betrayer.
Achieve the maximum upgrade level of a weapon.