1) The film's environment.
The film has a beautiful environment which does not disappoint those who watch it. The dystopian future looks believable (with people living among destroyed cities) and the idea of using water as a currency is an original idea which is also quite believable.
2) The film's characters.
Though the film has let itself down door lacking development regarding the characters, the characters themselves have decent personalities and would be great if they had development. You've got a Sephiroth-inspired villain, an adorable yet cool protagonist (reminded me of Eren Yeager for some reason), a girl from the past who is not an annoying brat, a humorous supporting character with an annoying little sister, a tough military woman who really gives hope to the anime industry regarding strong female characters, three elders with Forest powers who were the ones who built Neutral City (the main city in the film)... if u ask me those characters are the sort of ones u need in an anime series.
3) The onbeantwoord questions.
Like I said, the film is not perfect. This is not just because of the lack of development, but also the fact that they tried to throw so much into the film (not in an overwhelming way) but in doing so they left a lot of onbeantwoord vragen which would be the ones you'd want to see in an anime to keep levels of suspense. Also, they do need to be answered. Even little things need answering (there's a moment in the film where the villain suspiciously closes this book when the girl is looking at it, but u never find out what the book is).
4) The missing characters.
This might sound like an odd one, but in the original trailer for the original film which was not released (known as "Spirit") we are shown a lot of interesting things. We see the girl walking like a prisoner among other people who are presumably from the past like her, we see a cyborg guy and we see someone who accompanies the protagonist. It would be great to see those characters - I believe that they were cut out simply because the story shifted and because the film would have been either too long of just had too much going on. However, if the film was an anime series, we would see these characters.
5) The soundtrack.
It's always good to have a beautiful soundtrack to accompany a beautiful atmosphere in an anime. Personally I get annoyed when I watch some anime with a bad soundtrack. A beautiful soundtrack completes any scene that takes place, and in this movie the soundtrack is amazing. Not to mention that both the opening and ending themes are beautifully sung and go well with the film. I'd love to watch an anime series of this movie with that same beautiful soundtrack.
6) The voice-acting.
I'm one of those people who likes English dubs, but actually this film had a lovely English dub which actually sounded better than the Japanese dub from time to time. The best English voice actor was definitely Agito's and some other characters probably would need new voice actors, but if the voice-acting was to be as bearable as it was in the film (or better!) then it would definitely be good to watch.
7) Development!
Yes, I have just mentioned this, but I didn't focus entirely on development itself. An anime series would allow the characters to develop, and not just in their personality. My main problem was Agito since he seemed to just become this super-strong cool guy just door touching the hand of the Forest, but if he was in an anime series then we could see him adjust to his powers. There are other things in this film that do need to develop such as character backstories and character relationships.
There u go. Those are my reasons for why I think that Origin would be a great anime series. I highly suggest that u watch this movie as it is good to make the mind think and come up with theories to fill in the gaps that the creators left, plus the film is beautiful in visuals and soundtrack. If u haven't seen the film and u have read this I want to know what u think: does it sound like a good anime series of not? And if u have watched this I'd like to hear your ideas too! But personally for me I'd want to see this remade into an anime series.
