Here is the full list of all 41 Pentiment achievements.
Finished Act 3.
Cut enough cookies for everyone at the Christmas feast.
Learn the mystery of the cats.
Get assistance climbing down the mine shaft.
Learn about Artemis and Apollo's frog plan.
Convince Jacob Estler to save Ottilia's home.
Get knocked out.
Convince Endris to find his sweetheart.
End Act I in the abbot's favor.
Get Matilda executed.
Convince Gernot to let you dig up the grave.
Get Wojslav to let you into the cellar.
Headbutt Werner.
Finished Act 2.
Get Hanna killed.
Get Guy killed.
Get Martin killed.
Get Aedoc his medicine.
Refuse to shoot at the deer.
Shoot the deer.
Discover the imposter.
Examine 10 flowers.
Do your penance.
Lose everything at Lansquenet.
Win everyone's money at Lansquenet.
Pet 5 animals.
Complain to Niko about your room.
Finished Act 1.
End Act I out of the abbot's favor.
Get Ottilia executed.
Get Lucky executed.
Get Ferenc executed.
Tell Jacob Estler immaterial gossip.
Have your hat stolen.
Solve Ferenc's cipher with the volvelle.
Encourage Paul to draw.
Spin wool as fast as the ladies.
Seduce Zdena.
Pass 5 dialogue checks.
Find the secret door to library.
Convince Illuminata to give you the French book.