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.
Defeated a boss in Time Attack without taking damage.
Conquered Boss Rush.
Conquered Boss Rush without a single retry.
Defeated a boss in Time Attack in thirty seconds or less.
Defeated the ruler of the Great Forest.
Filled out all monster details in journal.
Acquired at least one of every item.
Defeated a rare golden foe.
Restored all lost memories.
Completed the main story.
Cleared the game on Nightmare difficulty.
Overcame Gruda's trial.
Opened every treasure chest.
Mastered every skill.
Successfully used Flash Guard fifty times.
Enhanced a weapon or armor to its limit.
Filled out all material details in journal.
Amassed one million gold.
Successfully completed every quest.
Endured all of Zara's tickle sessions.
Purchased every piece of info from Mouse.
Opened the door to the Temple of the Sun.
Discovered every resource point.
Completed the Map of Celceta.
Acquired both halves of the Mask of the Moon.
Played extensively as Karna.
Played extensively as Frieda.
Cleared all obstructed paths.
Played extensively as Calilica.
Found all of Mishy's hiding spots.
Arrived in the ruined capital, Elduke.
Befriended all animals.
Proved your skill as a merchant.
Located the underground village of Danan.
Reunited with Eldeel at the Tower of Providence.
Played extensively as Ozma.
Successfully arrived in the Primeval Lands.
Achieved five hundred Skill Finishes.
Defeated two thousand enemies.
Achieved five hundred Excellent Kills.
Walked an extraordinary total distance.
Played extensively as Duren.
Achieved one thousand Aerial Combos.
Resolved the polluted river dilemma.
Defeated Duren in one-on-one combat.
Successfully used Flash Move fifty times.
Solved the mystery of the missing villagers.
Discovered a settlement in the Great Forest.
Played extensively as Adol.
Successfully rescued the trapped miners.
Began your adventure in Celceta.