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