Here is the full list of all 49 WORLD OF FINAL FANTASY achievements. It takes around 50-60 hours to unlock all of the achievements on Windows.
Obtained every achievement.
Recorded every last Mirage in the Mirage Manual.
Defeated every last opponent in the Coliseum.
Defeated 30 teams at the Coliseum.
Mastered 100 Mirage Boards.
Defeated the Cogna known as XG.
Opened every last treasure chest.
Braved and completed the new dungeons that appeared.
Found the secret area in every dungeon.
Fulfilled the requests of every last townsperson in need.
Added Tamamohimé to your roster.
Reached the true ending.
Completed every last intervention battle.
Joined forces with Shivalry to defeat the Golden Flan.
Defeated Ultros in Tometown.
Brought all seven of the Pleiad back in line.
Completed 30 intervention battles.
Chastised the fugitive Ifreeta.
Teamed up with Gilgamesh to stop the Bahamutian soldier.
Reached an ending.
Defeated every last murkrift Mirage.
Recorded an inconceivable number of Mirages in the Mirage Manual.
Learned the location of Castle Exnine.
Defeated many foes using any Magitek armor.
Cleared the sky of uncountable einhänders.
Thwacked a whole bunch of cactuars in a single thrashing.
Reached the final chamber of the Nether Nebula in record time.
Obtained every last Champion Medal.
Found all of the keys from the Crimson Prophecy.
Defeated the Quacho Queen with one of Lann’s attacks.
Completed 10 intervention battles.
Battled 500 times.
Mastered your first Mirage Board.
Opened 100 treasure chests.
Recorded a huge number of Mirages in the Mirage Manual.
Got to the bottom of the “phenomenon” at the Coliseum.
Found the first key from the Crimson Prophecy.
Defeated the Undead Princess 10 times.
Recorded a large number of Mirages in the Mirage Manual.
Defeated the Princess Goblin with the Warrior of Light.
Battled 100 times.
Defeated your first murkrift Mirage.
Obtained your first Champion Medal.
Completed your first intervention battle.
Fulfilled a townsperson’s request for the first time.
Won your first Coliseum battle.
Repelled the Bahamutian Army.
Imprismed your first Mirage.
Arrived in Grymoire.