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