Anyway, because of how much I love going on about just how awesome a game Xenogears is, I'd be willing to explain just exactly how much deeper and more complex it is than virtually any other story there is, Eastern or Western.
Depth: It explores an absurd number of themes and concepts, ranging from war, to history, to politics, to economics, to ethics, to religion, to God, to the nature and creation of the universe. It is by far the most philosophically deep story I've ever come across, implementing the ideas and concepts of Freud, Nietzsche, Jung, with a particularly deep exploration of existentialism; it's extremely emotive, with a strong sense of friendship, romance, love, tragedy, revenge, betrayal; the story affects the player in virtually every way, at times genuinely terrifying you, at times genuinely shocking you, at times keeping you intrigued, at times keeping you excited, at times making you laugh, at times keeping you completely in the dark. There's a heavy use of symbolism throughout the game, and each and every single character, from the primary protagonists to the supporting protagonists to the antagonists of the storyline all receieve an extremely detailed backstory and role throughout the story. The villains are extremely well characterised; you have the mastermind in the form of Krellian, a sort of rival type figure in the form of Rhamsus, the intriguing villain in the form of Grahf, the genuinely terrifying Mhiang, the extremely cryptic Gazel Ministry, the extremely mysterious Id, the villain you grow to truly hate in the form of Stein, and many others. And before you think that it tries to pull too much off; all of those themes and concepts are explored over a 50 hour+ long story, and are all developed and introduced at an extremely great pace.
Complexity: The story presents the player with an absolutely unprecedented level of mystery and suspense, where events and characters can appear to be completely unrelated and seem that way for large portions of the story and then connect together far later on in the game. The story is filled with ridiculously cryptic characters and dialogue, that will genuinely confuse the hell out of you. The game explores a deep history, that's presented to you in an extremely unordered manner that further adds to the confusion. A lot of players still don't understand a large portion of the game's events, though they're mostly later explained towards the end of the game. You can literally spend days analysing the storyline. Really, it's hard to put into words just how complex it is but truthfully nothing else I've come across (which includes Neon Genesis Evangelion) even comes close.
The truth of the matter is that nothing else comes close in those regards and that Xenogears is quite simply far deeper and more complex than any other story out there. And beyond that it's music is absolutely incredible and really enhances the mood and atmosphere of an incredible well told and emotive story.