Here is the full list of all 52 Ys: Memories of Celceta achievements. It takes around 50-60 hours to unlock all of the achievements on Windows.
Acquired all achievements.
Cleared the game on Nightmare difficulty.
Conquered Boss Rush.
Conquered Boss Rush without a single retry.
Defeated a boss in Time Attack in thirty seconds or less.
Defeated a boss in Time Attack without taking damage.
Acquired at least one of every item.
Filled out all monster details in journal.
Mastered every skill.
Played extensively as Ozma.
Opened every treasure chest.
Played extensively as Calilica.
Restored all lost memories.
Completed the main story.
Overcame Gruda's trial.
Played extensively as Frieda.
Completed the Map of Celceta.
Opened the door to the Temple of the Sun.
Defeated the ruler of the Great Forest.
Enhanced a weapon or armor to its limit.
Discovered every resource point.
Successfully completed every quest.
Filled out all material details in journal.
Purchased every piece of info from Mouse.
Endured all of Zara's tickle sessions.
Acquired both halves of the Mask of the Moon.
Played extensively as Karna.
Cleared all obstructed paths.
Found all of Mishy's hiding spots.
Amassed one million gold.
Achieved five hundred Skill Finishes.
Arrived in the ruined capital, Elduke.
Successfully used Flash Guard fifty times.
Befriended all animals.
Played extensively as Duren.
Located the underground village of Danan.
Proved your skill as a merchant.
Reunited with Eldeel at the Tower of Providence.
Walked an extraordinary total distance.
Achieved one thousand Aerial Combos.
Successfully arrived in the Primeval Lands.
Defeated two thousand enemies.
Defeated a rare golden foe.
Successfully used Flash Move fifty times.
Resolved the polluted river dilemma.
Played extensively as Adol.
Defeated Duren in one-on-one combat.
Solved the mystery of the missing villagers.
Achieved five hundred Excellent Kills.
Discovered a settlement in the Great Forest.
Successfully rescued the trapped miners.
Began your adventure in Celceta.