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 without taking damage.
Defeated a boss in Time Attack in thirty seconds or less.
Enhanced a weapon or armor to its limit.
Acquired at least one of every item.
Filled out all material details in journal.
Amassed one million gold.
Defeated the ruler of the Great Forest.
Purchased every piece of info from Mouse.
Endured all of Zara's tickle sessions.
Proved your skill as a merchant.
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.
Completed the Map of Celceta.
Discovered every resource point.
Defeated a rare golden foe.
Played extensively as Calilica.
Mastered every skill.
Opened every treasure chest.
Successfully used Flash Guard fifty times.
Played extensively as Ozma.
Opened the door to the Temple of the Sun.
Successfully completed every quest.
Played extensively as Frieda.
Acquired both halves of the Mask of the Moon.
Played extensively as Karna.
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.
Successfully arrived in the Primeval Lands.
Defeated two thousand enemies.
Walked an extraordinary total distance.
Played extensively as Duren.
Defeated Duren in one-on-one combat.
Solved the mystery of the missing villagers.
Achieved five hundred Excellent Kills.
Achieved five hundred Skill Finishes.
Played extensively as Adol.
Resolved the polluted river dilemma.
Achieved one thousand Aerial Combos.
Successfully used Flash Move fifty times.
Discovered a settlement in the Great Forest.
Successfully rescued the trapped miners.
Began your adventure in Celceta.