Here is the full list of all 33 Ys: The Oath in Felghana achievements.
Spent over 10 hours in a single playthrough.
Completed all other achievements.
Killed 2,000 Mozgouz across all playthroughs.
Escorted Elena to safety on every difficulty level.
Escorted Christof to safety on every difficulty level.
Achieved max level.
Defeated "The Deadliest Cuteness."
Beat the game on Hard.
Beat the game on Nightmare.
Beat the game on Inferno.
"Measured" Elena.
Sold Randolph's ring to Cynthia.
Defeated the final boss without taking any damage.
Killed 500 Selnades across all playthroughs.
Bested the master of the mountains in one-on-one combat.
Conquered Boss Rush on Nightmare.
Conquered Boss Rush on Hard.
Maxed out all equipment.
Beat the game in under 5 hours.
Enabled "No-Fall" mode.
Began the game on Very Easy.
Conquered Boss Rush on Normal.
Beat the game on Very Easy.
Beat the game on Easy.
Beat the game on Normal.
Acquired every jewel.
Encountered every enemy in the game, excluding bosses.
"Killed" 50 immortal beasts without using the Silver Chimes.
Spoke with every character in the game at least once.
Defeated 5 or more enemies (except Mozgouz) at the same time.
Saved all of Hugo's pikkards.
Completed Anya's treasure-hunt game.
Died over 10 times on a single boss.