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