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