Wild Arms 4

You play as a young teenager named Jude Maverick. You live in a quiet village that floats high above the ground, unaware of the world that lies beneath it. But one day, your world is shattered to pieces, and you descend onto the earth to face the terrible reality: the world of Filgaia was devastated by wars.

A few settlements amidst rusty tanks is all that is left of civilization.