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