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