It's mediocre, but faintly charming. It's a post-apocalypse underwater SF fable and one of Japan's first all-CGI anime.
The story is straightforward and sincere. We begin in space. Mum, Dad and their daughter Amamiku are flying towards Earth in their spaceship when suddenly the planet's surface blooms with nukes. Ninety years later, Amamiku is still a little girl. She lives at the bottom of the ocean in the same spaceship, alone except for a computer that always knows best and a little robot. Her parents are dead. They caught enough radiation during planetfall that they decided not to join their daughter in cryo-sleep. There's a sweet scene of her watching a holo-recording of them saying this ninety years ago.
Anyway, Amamiku's a nice enough child. She's perhaps a bit shallow and bad at taking the long view, but what do you expect at her age? The computer has to prod her to do her regular checks and protect herself from radiation... because, you see, they have a mission. They have seeds. Jack and the Beanstalk had nothing on these babies. When the time is right (handwave alert?), they're going to release their seeds and bring life back to the Earth. Imagine trees that can manage hundreds of years' growth in about thirty seconds, then sprout human foetuses from their branches like fruit.
This is a noble mission and they believe in it. That's what the good guys want... but there's also a bad guy with the awesome name of Glptofane Sex. That's not even the best thing about him. He's a disembodied brain with googly eyes, Frankenstein-style bolt-ons and siblings who are walking nervous systems. This is the coolest thing in the movie. At one point I thought I heard someone say they were pure will, perhaps suggesting that their physical forms aren't real and so they can't be killed, but I'm not sure how that would fit with later developments. Anyway, Glptofane Sex believes that as long as the human race is still alive, there's no way for the Earth to recover. Does that mean he caused a global nuclear holocaust for the sake of the environment? Hmmm. He and his siblings believe in "the absolute law", which they discuss in neo-theological language as if it's the will of God and of which Glptofane Sex thinks he's the sole arbiter. His beef with humans is that they're arrogant. Once again, hmmmm. Apparently we think only of our own existence and not of the world around us, which seems a reasonable enough allegation.
In other words, Glptofane Sex is great. His personality and motivations are nothing special, but he looks fantastic and it doesn't hurt the story for him to have logical flaws in his thinking. If villains were intelligent and sensible, they wouldn't be villains.
Thus an earnest story begins. Everyone believes in the environment, the beauty of the planet and the holy mission of protecting all life thereon. Glptofane Sex just happens to be a bit more doctrinaire about it. Nothing that happens in this film will surprise you, but sometimes simplicity is a virtue. The running time is short, the plot doesn't try to do too much and it puts its message forcefully without being an eye-roller. A bit more characterisation wouldn't have hurt, but in a way the simplistic, near-iconic nature of the characters almost helps.
Then there's the CGI.
It's ancient, obviously. It's 2001. You can't even say it looks like a video game because the best of today's video games look better. The spaceships, wacky disembodied brains and undersea landscapes are all beautiful enough to make me happy that they chose CGI, but the humans are of course ludicrous. However in a way, this aspect of the animation is so primitive that it becomes almost a feature. It's like watching a Gerry Anderson show. They look like puppets. They have the same stiff postures and faces. There's no uncanny valley because they don't even make it that far... to be creeped out by a CGI character's eyes, you've got to accept some level of constrasting reality in the rest of him. Here, nope. I didn't even realise Amamiku was a girl until the dialogue referred to her gender. It doesn't look like my conception of anime, but I've seen Japanese puppet dramas (e.g. Go Nagai) and it's like them.
The explosions are a missed opportunity, though. When stuff blows up underwater, we see fireballs (eh?) and then on one occasion fish still alive in the vicinity and swimming away (um, no). Don't these people know what happens when something explodes underwater? The annoying thing is that CGI would have been the perfect medium for doing this realistically, if you programmed a simulation of fluid dynamics, but instead there's no visible difference with the explosions in any other film on dry land. Shame.
Apparently this film was commissioned by the Okinawan tourist board and is set in the seas near Okinawa. It's supposed to be beautiful there. I'm not sure the plot makes sense (e.g. how come it's suddenly okay to come to the surface at the end?) but the story's so heartfelt that it's hard to hold that against it. Besides, maybe I missed something. There's idiosyncratic philosophy, a passion for the film's environmental message and a lot of beautiful imagery. Even back in those days, CGI could make this kind of stuff look gorgeous. It also feels even shorter than it is. Sincere, sweet and simple.