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