Here is the full list of all 43 CODE VEIN achievements. It takes around 60-80 hours to unlock all of the achievements on Windows.
Explore every part of the depths
Learn 150 Gifts (excluding those learned when acquiring a blood code)
Restore all Vestiges
Upgrade a weapon to its maximum level
View the "Dweller in the Dark" ending
Defeat the Skull King in the Gaol of the Stagnant Blood
Activate all mistles
Defeat the Queen's Knight Reborn in the provisional government outskirts
Upgrade a Blood Veil to its maximum level
View Murasame's memory echoes
Defeat the boss of the Crypt Spire, Juzo Mido
Defeat the Blade Bearer and Cannoneer in the Crypt Spire
Defeat the Successor of the Throat in the Crown of Sand
Defeat the Successor of the Claw in the City of Falling Flame
View Mia's memory echoes
Defeat the Gilded Hunter in the Ashen Cavern
Defeat the Successor of the Breath in the Ridge of Frozen Souls
Execute a Communal Gift
View Io's memory echoes
Defeat the Successor of the Ribcage in the Cathedral of the Sacred Blood
Equip every weapon type
Unlock the ability to inherit 50 Gifts
Defeat the Queen's Knight within your memory
Equip every Blood Veil type
Learn 50 Gifts (excluding those learned when acquiring a blood code)
View Davis's memory echoes
Defeat the Insatiable Despot in the dried-up trenches
View Yakumo's memory echoes
Defeat the Invading Executioner in the Howling Pit
View Coco's memory echoes
View Louis's memory echoes
Defeat the Butterfly of Delirium in the ruined city center
Give a desired valuable to a friend
Defeat Oliver Collins in the ruined city underground
Listen to partner conversations 50 times while exploring
Successfully use a special drain from a parry, back attack, or launch attack
Unlocked all other achievements
View every ending
Receive 30 presents from friends
Raise your reputation as a companion to rank 30
Collect every blood code
View the "Heirs" ending
View the "To Eternity" ending