Full list of all 18 Final Fantasy achievements worth 200 gamerscore. It takes around 50-60 hours to unlock all of the achievements on Windows Phone.
Completed the 15 Puzzle within 30 seconds.
Defeated Chronodia in all forms.
Completed entire Soul of Chaos.
Defeated 5,000 monsters.
Completed game within 8 hours.
Defeated Chaos.
Defeated Tiamat.
Defeated Warmech.
Defeated the Kraken.
Set foot in every monster-free town and castle.
Acquired the Airship.
Defeated Marilith.
Defeated the Lich.
Acquire 100,000 gil.
Defeated 1,000 monsters.
Took 10,000 steps.
Crossed the bridge north of Cornelia.
Defeated 100 monsters.