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