There are ultimately two nicknames which can be given to Origin:
Avatar: The Anime Edition or The Poor Man's Princess Mononoke.
Take your pick, they're both accurate in their own way and convey the problems of the anime's story. It has brilliant visuals which try to make up for a very poor script and is the usual "nature vs. industry" morality play, with a heavy dose of "SCIENCE BAD!!!"
Set centuries into a post apocalyptic future, humanity and earth's ecosystem have been ruined by a conflict between themselves and bio-engineered sentient plants. Created to assist in colonising news worlds, the plants escaped confinement, murdering billions in the process, destroying the moon and bringing civilisation to its knees.
In the plant overrun Neutral City which acts as a barrier between the sentient Forests and the technologically advanced nation of Ragna, ruled by the humans turned into upright walking plants, a remnant of the old world is found. A young woman frozen in cryogenic stasis who, when awakened, seeks to destroy the Forest and end the conflict for good...
I'm going to make this clear right out of the starting gate: The film is heavily weighted on the side of the Forest. While a few efforts are made to try and give some kind of balance, showing the Forest to be willing to kill and withhold water at a moment's notice, we're ultimately expected to side with it. Despite effectively holding a tyrannical grip over any humans under its control and willing to blackmail, kill and threaten millions at a moment's notice, the plot ultimately sides with them.
The script tries to trump up some message of "merging" with the plants, which ultimately comes down to all humans being turned into trees and abandoning all technology. Ragna is represented as effectively being a militaristic fascist state with walking tanks, and the humans merged with the Forest are seen as living perfect lives. With, of course, the added bonus of being turned into superhumans who can easily wreck tanks with their fists.
So yes, if you thought the na'vi were raging hypocrites who were only the heroes thanks to the director's love for them, you're not going to like this one. It's preachy, bias, nonsensical and with a message which ultimately undermines itself as the film goes by. The closing shot is of the cryo-girl dropping the MacGuffin, signifying her abandonment of all technology and dreams of restoring the old world. This flies in the face of Ragna only surviving thanks to said technology, and even the plant dominated Neutral City using machinery.
Origin manages to undermine itself so continually you could honestly create a drinking game based upon spotting these moments.
Still, a poor story can still be saved by great characters right? Yes, but you'll be lucky to find anything decent here. Even after watching this one twice over, along with going back to multiple scenes to check facts, I still couldn't remember anyone's name by the time it came to writing and had to visit IMDB.
The cryogenically frozen girl, Toola, has a painfully obvious arc and little character beyond it. While a handful of moments of her remembering the old world do begin to feel meaningful, she is such a cipher that they have nothing to work off of. There should truly be a great deal for her to go with, her entire world is gone, but all she manages to be is a messenger for the film's broken anti-technology message.
Agito, the boy who finds her, meanwhile is only memorable because by the third act nothing is a threat to him. Once he gains superpowers, he becomes unstoppable to the point where you might as well be repeatedly looking at your watch to check how long Origin has to go.
The others prove to be more or less what you expect, with Ragna's representatives either being depicted as generically villainous or woefully misguided in an effort to have the audience side with the genocidal Forests.
If there is one thing the film does get right, it does have great visuals. The ruined landscapes, designs of clothing and various locales are all beautifully depicted in their own way, despite some fairly conspicuous CGI. You'll be left with some great images and there is obvious talent on display, and elements of the characters do seem to be aping studio Ghibli designs quite often. Actually that likely sums up the film well: It's a soulless copy of a Ghibli production done by someone else.
If you've not gotten this by now, Origin is not a good film. There could have been something great here, but you'll probably just be left thinking "Why am I supposed to be wanting the murderous plants to win again?" or more likely "I've seen this done before and much better."
If you want a good version of this, go seek out Nausicaä of the Valley of the Wind. Either the manga or the film will do. You'll get the same themes as here, but they're told in a way which won't leave you wanting to take a chainsaw to the nearest shrubbery.