Here is the full list of all 40 The Forgotten City achievements. It takes around 12-15 hours to unlock all of the achievements on Windows.
Talk your way through every possible confrontation
Reach the best ending with the smallest number of loops
Lie 10 times
Dodge 3 boulders
Free the captive and shoot her captor with your gun
Topple 10 peeled statues by kicking others into them
Die from hornet stings
Finish the game without looping through time once
Reach Ending 1 of 4
Loop through time ten times
Trigger The Golden Rule by stealing 5 times
Reach Ending 4 of 4
Assemble as many people as possible in the Museum
Intimidate the creator of The Golden Rule
Confront the creator of The Golden Rule
Reach Ending 3 of 4
Reach Ending 2 of 4
Have Duli released from his cell
Allow Fabia to die in the collapsing temple
Steal 2000 coins after the Golden Rule is broken
Help Galerius romance Equitia
Find all three missing persons
Enter the upper cistern in an unconventional way
Solve Vergil's problem
Save Ulpius's life
Read 10 different grafitti
Discover Underworld icons Sisyphus, Tantalus, Ixion and the Belide
Find treasure using the golden bow
Survive the Palace
Use Photo Mode
Gild your first thing
Pick up the sponge on a stick
Save Iulia's life
Discover what lies beneath the city
Learn the true identity of the stranger by the river
Save Fabia's life
Skip the city tour
Loop through time once
Enter a villa with a daring leap
Get rejected by Aurelia