I don't know how much you know about the game, so bear with me if you already know some of this:
You start out as a flute player who joins up with a troop of fighters going around to destroy the chains that bind the moon to the earth. The chains are there because the people in this fantasy world receive power from the moon and the enemy organization wants more power yadda yadda yadda... you look just like the leader of the group, the group leader is killed, you are forced to take his place traveling around destroying these chains because the moon's power is fucking people over (Natural disasters, attracting monsters who attack people, etc...). The chains are all connected by this orb at the tethering point that you have to cut through which makes the chain break apart and dissolve.
As it comes to the end, you win over the love interest as you head off for the last chain. When you get there, you realize that the orb you have to cut is on the moon itself. You then proceed to walk up the chain (with the aid of magic, admittedly) to try and find the tethering point on the moon. Once you are done walking to the moon (done in a cutscene) you fight the leader of this organization again, who has been powered up by the moon god himself. You beat him, then the moon god offers you the position of the guy you just killed, tethering more chains to the earth. Thus begins boss battle part deux, wherein you kill the fucking moon god.
All that's left is to cut the chain right? But wait! if we cut the chain, we'll be stuck here! So the hero tells everyone to start running down the chain so he can cut it and he'll stay behind. The love interest pitches a tantrum, but after a tearful goodbye from everyone else, she is carried kicking and screaming back down from the moon. The chain is then cut.
Once back down on the surface, the troop learns that by killing the moon god, all of those who had gotten the most power from the moon (known in this game as an "Aristo") is now about to slip into a coma. For the record, Aristo is short for exactly what you think it is short for: Aristocrat. That's right, by killing the moon god, by extension we just killed EVERY world leader.
Roll Credits, wait for epilogue...
THREE YEARS LATER!
The love interest has become the queen of her country and is overseeing the reconstruction of one of the ruined towns. All of a sudden, her pet bear runs off into a field, apparently alerted to something. She chases it, comes up over the crest of the hill, and there stands the hero, under a tree, playing his flute. She falls into his arms and cries tears of joy saying she thought she'd never see him again.
Fin.
No explanation of how he got down from the moon, no nothing.
In short: They walked to the moon, killed god, ripped off the movie Armageddon, killed off every world leader simultaneously (both the good and the bad), and wrapped it all up with an inexplicable happy ending. What the fuck.