Here is the full list of all 17 Ys I Chronicles+ achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Completely fill the character notebook.
Make Dogi break through three different walls.
Rescue Luta Gemma from monsters in the field.
"Measure" Feena.
"Measure" Feena in the creepiest way possible.
Level-up Feena.
Confuse and astound the townsfolk.
Drive a hard bargain with Pim.
Receive a free Short Sword.
Max out your money.
Complete Ys I on any difficulty.
Listen to Reah recite her poem.
Receive a free Talwar prior to entering the tower.
Unlock all details for all non-boss bestiary entries.
Complete Ys I on Nightmare difficulty.
Complete Ys I Time Attack.
Master every achievement in Ys I.