Here is the full list of all 50 Dishonored 2 achievements. It takes around 40-50 hours to unlock all of the achievements on Windows.
Eliminate 20 unaware enemies
Reached Karnaca
Finish an entire mission with no casualties
Recovered your signet ring
Dealt with Dr. Alexandria Hypatia
Found Anton Sokolov in the Clockwork Mansion
Visited the past
Took Delilah’s soul
Eliminated Duke Luca Abele
Saved your last known family member
Save the Printer of the Dunwall Courier
Steal a corpse for Mindy Blanchard
Stop the Grand Guard from pushing someone into the Wall of Light
Drop from Addermire’s highest point and take out an enemy below
Chat with Dr. Hypatia aboard the Dreadful Wale
Kill Paolo three times
Eliminate Jindosh without him ever knowing you were there
Listen to the voices of the Sisters of the Oracular Order
Side with the Howlers in the Dust District
Side with the Overseers in the Dust District
Crack the Jindosh Lock without finding the solution elsewhere
Obtain Stilton’s Master Key from under the table, with the guards there conscious & unalerted
Drain the water to recover a Rune
Find the hidden balcony passageway
Heard Meagan Foster’s story
Pay tribute to Jessamine one last time
Rob Galvani multiple times
Link 2 characters with Domino just before one kills the other
Score a headshot while sliding
Craft 10 Bonecharms
Eliminate 6 enemies in less than 1.5 seconds
Kill an enemy with their own bullet
Cast Possession once, chaining between human, hound, rat, fish, and bloodfly
Finish an entire mission without being spotted
Rob a black market shop
Find 60% of available loot
Collect all the decorative objects for the Dreadful Wale
Using the Heart, listen to the secrets of 40 different people
Obtain numbered plates for 3 Clockwork Soldiers
Acquire all collectible paintings
Peruse all journals and audiographs by Meagan Foster and Anton Sokolov aboard the Dreadful Wale
Find 3 musical duos across Karnaca, and listen to their songs
Eliminate 10 enemies with Drop Assassination
Finish the game without being spotted
Complete the game without supernatural powers
Finish the game with Corvo Attano
Finish the game with Emily Kaldwin
Complete the game in low chaos
Complete the game in high chaos
Complete the game without killing anyone