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