Here is the full list of all 38 Dark Souls II achievements. It takes around 60-80 hours to unlock all of the achievements on Windows.
Earn all achievements
Inherit Benhart of Jugo's equipment
Discover the abysmal covenant
Learn all pyromancies
Learn all miracles
Learn all gestures
Learn all sorceries
Discover the covenant of the fittest
Learn all hexes
Inherit equipment from Lucatiel of Mirrah
Inherit Laddersmith Gilligan's equipment
Inherit Steady Hand McDuff's equipment
Discover the covenant of the bloodthirsty
Light all flames on the map in Majula
Inherit equipment from the head of Vengarl
See the ending
Defeat Vendrick
Inherit Captain Drummond's equipment
Discover the covenant of rodents
Discover an ancient covenant
Acquire Ashen Mist Heart
Max-out devotion to covenant
Acquire the King's Ring
Defeat Looking Glass Knight
Reinforce a weapon to its limit
Light the primal bonfire in Brightstone Cove Tseldora
Light the primal bonfire in the Black Gulch
Increase the population of Majula
Give Rosabeth of Melfia something to wear
Light the primal bonfire in the Iron Keep
Discover the clangorous covenant
Reclaim flesh and set out as an Undead
Light the primal bonfire in Sinner's Rise
Discover the covenant of the meek
Defeat the Last Giant
Discover a most brilliant covenant
Discover the covenant of the protectors
Die for the first time