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