I just watched this for the first time today and WOW! I've always been a huge fan of the Studio Ghibli films but this is by far my favorite.
I just loved the environmentalist themes running through it (something I really enjoy in the Ghibli films) as well as the sci-fi aspect of it, more over the story was just enthralling and kept me sucked in all the way through.
I even liked the dubbing in it which was surprising as I usually hate watching foreign films that have been dubbed especially animes as they seem to always hire the most unfitting voice actors available, typically a guy with the voice of Barry White for a 12 year old boy in the lead role which can get a tad irritating, but the chick who was in the lead was pretty good and one of the supporting characters is voiced by Patrick Stewart and lets face it you cant go wrong with his voice.
Full marks from me, so go buy/rent/watch this movie now if you're a fan of a good sci-fi or just love films with great stories.
Awesome film, I deffo rate it up there with Princess Mononoke, Spirited Away and other Hayao Miyazaki masterpieces everything i've seen from Studio Ghibli i've really enjoyed actually.
From what i've seen though, a lot of people here and on SS.org snub anything that's "anime" but their loss, there are some incredible films, short films and TV series out there, anime doesn't start and end with naruto and pokemon