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.
Acquired at least one of every item.
Filled out all monster details in journal.
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.
Restored all lost memories.
Completed the main story.
Overcame Gruda's trial.
Played extensively as Ozma.
Opened every treasure chest.
Enhanced a weapon or armor to its limit.
Mastered every skill.
Filled out all material details in journal.
Completed the Map of Celceta.
Played extensively as Karna.
Played extensively as Calilica.
Played extensively as Frieda.
Discovered every resource point.
Defeated a rare golden foe.
Amassed one million gold.
Achieved five hundred Skill Finishes.
Played extensively as Duren.
Defeated the ruler of the Great Forest.
Successfully completed every quest.
Cleared all obstructed paths.
Achieved five hundred Excellent Kills.
Endured all of Zara's tickle sessions.
Purchased every piece of info from Mouse.
Opened the door to the Temple of the Sun.
Acquired both halves of the Mask of the Moon.
Found all of Mishy's hiding spots.
Arrived in the ruined capital, Elduke.
Defeated two thousand enemies.
Befriended all animals.
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.
Successfully arrived in the Primeval Lands.
Successfully used Flash Move fifty times.
Resolved the polluted river dilemma.
Achieved one thousand Aerial Combos.
Defeated Duren in one-on-one combat.
Played extensively as Adol.
Solved the mystery of the missing villagers.
Discovered a settlement in the Great Forest.
Successfully used Flash Guard fifty times.
Successfully rescued the trapped miners.
Began your adventure in Celceta.