I really don't like when people are writing reviews by the truckload after only reading the first dozen or so chapters of the manga. And considering the age (and the scores) of the reviews currently present on the site, all of them seems to be from the time when only the first half of the manga was available. That explains all the 9s and 10s. Heck, I would've give it a 9 or 10 around the 30th or 40th chapter. But after the strong start the quality only goes down until the end, which is quite honestly the worst trainwreck of an ending I've seen in a long while. So, let's get started.

Story - 3 (Poor)
The set up is good. A bunch of high-schoolers stranded up on a strange, mysterious and quite hostile island. Add together the first season of Lost and the Lord of Flies and you get the early chapters of Eden no Ori. Awesome? Yes. Promising? Yes. The problem is, that the manga never really fulfils this promise. In the early chapters there's no real story to speak of: our heroes move from one place to another trying to survive, while constantly expanding the settings and the characters. However, this becomes kind of stale soon enough: in every arc, the manga introduces a bunch of characters, some good guys and a greater number of douches (yes, it's that easy to distinguish). By the end of the arc, the good guys usually survive and join up with the protagonist team (and becoming insignificant almost instantly), while the baddies get eaten by something nasty. Rinse and repeat for around a hundred chapters. There are a few surprises along the way, but what keeps you reading is the number of mysteries piling up. You want answers. You want explanations and conclusion for the also increasing number of plot-threads. And this is why I gave such a low score: you'll get NONE of these. The explanations come in a form of science, that does not work that way. Some plot-threads get completely forgotten (Hades for one). And as for conclusion, the last few chapters were supposed to be the big reveal, putting everything to place and explaining all the mysteries. Supposed is the keyword here: they explain nothing. They just add to the number of question marks. The entire conclusion is illogical, rushed and nonsensical in general. I could rage on for pages why and how, but I don't want to give away any specific spoilers, so I refrain from doing so. Now add complete asspull plotwists, cardboard cut-out, cartoonishly evil bad-guys, ridiculous monsters, science defying the laws of nature, abundant fan-service and the fact that all of this is played 100% straight; so you are supposed to take everything here seriously, when some parts would be just too stupid even for a parody, and you get the reason behind the score given for this segment.

Art - 8 (Very Good)
Ok, I admit that this is not my field of expertise. I'm a writer, but I couldn't draw anything to save my life. So maybe I go too easy on the manga in this aspect, but I loved the art. The ancient mammals really came through as fearsome animals. The surroundings are also really atmospheric, sometimes downright eerie. My only serious complaint would be that while the main characters are well-drawn, some of the sidecast (especially the guys who are only around for one arc) are not so, and sometimes I got them mixed up. But with this huge cast, that's forgiveable I guess.

Charactrer(s) - 4 (Decent)

Decent, although barely. The characters are flat and never really get any development. They're go through this typical shounen change: shit happens, and they are suddenly either become complete jerks, or heroes. Now, in the first part, this isn't too much of a problem, since it's somewhat compensated by the number of characters getting introduced constantly. However around the time when the survival part ends and the evil doc comes into the picture, the constant flow of new charactes stop and the manga focuses on the already existing team. And this is where it becomes painfully obvious, that beyond the little background info shared in their own arcs, there's nothing else going for any of the characters. The relationship between them is just as stale, as the characters themselves. Take the "romance" between the protagonist and his main love interest. Both of them are donkans. Yay. At one point, while protecting Rion's (supposedly) unconscious body, Akira literally shouted this in one of the antagonists' face: "This is my woman! Got a problem with that?!" And even this didn't pushed their relationship even an inch forward. No comment.

Enjoyment: 5 (Mediocre)

Well, on an average at least. The survival part is friggin' awesome, I loved every chapter of it. After that, as the story was becoming more and more idiotic and I lost interest. In the last few chapters the only "enjoyment" I got was awkwardly laughing between facepalms. So starts out as 10, ends as 1, thus on average 5.

Overall: 6 (Overall)
It's a real shame what has this manga become in the end. When it started it had some much potential, showed so much promise. Hell, it easily could have been a timeless classic. But as time and chapters passed by, it descended lower and lower in the abyss of asspull and bad writing. I could still kinda-sorta recommend it as long as you don't have any expectations. It's awesome in the beginning and even later it's still kind of fun for a while.