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