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.
Unlock all details for all non-boss bestiary entries.
Slaughter ten generations of gatekeeper.
Completely fill the character notebook.
Max out your money.
Eliminate all the monsters in Gila's basement.
Scatter apples violently across the floor, most likely bruising them horribly.
Complete Ys II on Nightmare difficulty.
Complete Ys II Time Attack.
Receive money from a duck.
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.
Ensure that Maria is not amused.
"Measure" Tarf.
Raise Tarf to max level.
Sleep in three women's beds.
Oh God make them go away!
Find and speak with Aldow.
Master every achievement in Ys II.