Here is the full list of all 45 Blasphemous achievements. It takes around 25-30 hours to unlock all of the achievements on Windows.
Cross the Bridge door in less than 3 hours.
Beat all bosses without flask consumption.
Provoke the meeting between Redento and Cleofás.
Beat Esdras, of the Anointed Legion.
Get 100% of the game.
Unlock the ending A.
Get all rosary beads.
Beat all the arena challenges.
Get all sword hearts.
Unlock the ending B.
Beat His Holiness Escribar.
Discover all zones.
Beat Crisanta of the Anointed Blade.
Talk with all the corpses.
Buy all skills from the Mea Culpa shrines.
Achieve the maximum level of the Mea Culpa sword.
Get all prayers.
Achieve the maximum value of rosary bead slots.
Achieve the maximum value of flasks.
Save all Kissers of Wounds.
Achieve the maximum value of health.
Beat Quirce, Returned by the Flames.
Release all cherubs.
Get all collectibles.
Achieve the maximum value of fervor.
Beat all types of enemies.
Help Cleofás in his path of redemption.
Bring all the offerings to the Blessed Lord of Salty Shores.
Get all relics.
Bring all the offerings to Lvdovico.
Beat Melquíades, The Exhumed Archbishop.
Help the Pilgrim reach his final destination.
Beat Exposito, Scion of Abjuration.
Visit the tomb of The Lady of the Tailed Gown.
Buy all the items of the Candelaria shops.
Execute 5 different enemies.
Hatch the Egg of Altasgracias.
Witness the last moments of Viridiana.
Beat the Tres Angustias.
Kill 666 enemies.
Beat Perpetua.
Beat the Our Lady of the Charred Visage.
Beat Ten Piedad.
Use the Righteous Riposte 5 times.
Beat the Warden of the Silent Sorrow.