As noted above, the
plot of Xenogears is just so
complex (not to mention
epic and
engaging) that to write it all would be nearly impossible. I have completed the game, and I honestly cannot remember 75% of the whole story, it's just that
huge.
However, it is possible to paraphrase the actual idea behind the plot. If you intend to play Xenogears it's highly advisable you do not read the following. (also note: I'm just remembering this so feel free to correct)
Basically, long before life (or atleast, sentient life) existed on Earth, a space freighter of a long extinct race was flying near our humble planet, carrying within it a terrible monster. I do not remember what the freighter was planning to do with the monster, but, as the really cool intro to Xenogears illustrates, the monster has other plans, and wrecks the ship, crashing it on the surface of a desolate Earth.
Unfortunately for the monster, it has been injured in this manuever, and needs to rejuvenate itself. So, it creates a woman, 'Eve' ('she' is referred to by a whole bunch of names throughout the game.) With this 'Eve' the monster slowly but surely creates the entire human race.
Now, I cannot recall the exact purpose the monster had for humanity, other than that ultimately he would use them (fatally) to revive himself. I believe it was a combination of human technology and the usual life force draining move that so many villians are fond of.
Anyway, in the process of doing this, the monster builds human religion to ensure that they will not deviate from their ultimate purpose. Thus, throughout most of the game, the monster is referred to as God, and, perhaps even more controversially, the protagonist is referred to as the Slayer of God.
There are far more levels to this than this brief paraphrase can hope to recall, and literally dozens (if not hundreds) of other plots that take place from the fateful crash of that space freighter to the ultimate conclusion of the story.
However engaging and fun Xenogears was for me, I have one major gripe. The first disc of the game (which comprises the majority of the story, thank goodness) is absolutey awesome and epic. The second disc is another matter. It seems Square realized that making a plot like that of Xenogears was taking too long, so, they essentially took the majority of the story prior to the conclusion and crammed it into a few brief episodes of play and a whole bunch of monologues by the main characters.
Perhaps this was for the best. Xenogears is about 70 hours long. To include that missing portion of the story would take atleast another 70. To follow a game 140 hours in length, no matter how much fun would be a feat. Still, I can't help but feel a little jipped.