Here is the full list of all 21 Ys II Chronicles+ achievements. It takes around 12-15 hours to unlock all of the achievements on Windows.
Complete Ys II on any difficulty.
Slaughter ten generations of gatekeeper.
Ensure that Maria is not amused.
Eliminate all the monsters in Gila's basement.
Receive money from a duck.
Completely fill the character notebook.
Unlock all details for all non-boss bestiary entries.
Complete Ys II on Nightmare difficulty.
Complete Ys II Time Attack.
Scatter apples violently across the floor, most likely bruising them horribly.
Receive a free Short Sword.
Burn 50 villagers.
Make all the animals in Ramia Village absolutely adore you.
Receive and eat four unique homemade food items.
"Measure" Tarf.
Raise Tarf to max level.
Sleep in three women's beds.
Oh God make them go away!
Find and speak with Aldow.
Max out your money.
Master every achievement in Ys II.