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