I can't have been that enthralled by ep.1. I'd thought it looked good at the time, but I still dropped it. It had a fairly dry story and CGI animation by Polygon Pictures, the 3DCG studio who also did Transformers Prime and Star Wars: The Clone Wars. (It's been cel-shaded, but you can tell it's built in a computer.) The cinematography looked fantastic. The battles looked even better. Even the atmosphere and sense of futuristic SF culture were impressive. However the people looked like Barbie dolls and I couldn't tell them apart.
I hadn't been planning to watch any more, but then recently I noticed that the show had got a second series and quite a lot of praise. I gave it another go. In short, it gets better.
It took the characters quite a long time to come alive, especially given their anonymous and largely indistinguishable CGI character models. (Some of these people are clones of each other, by the way, just to make things easier.) At one point I even went online to try to find out whether Hoshijiro and Shinatose were the same character, thus discovering to my surprise that Hoshijiro was an important character who'd been around since ep.1. Gosh. Main characters like that should make more impression, surely? If the audience can't tell who's who, of course they're going to feel less involved. Of course I'd noticed that Hoshijiro has boobs (being female) and Shinatose doesn't (being a hermaphrodite), but I'd also remembered that a hermaphrodite's body would adapt to suit the requirements of his/her partner, so I'd been wondering if the boobs might have been simply an indication that Shinatose fancied Tanikaze.
However the plot grows teeth. Ep.4 made me want to watch the next episode, which was a first. The characters establish themselves and I learned to be able to distinguish them. One of them is one of the most loathsome human beings ever to unjustly avoid euthanasia, which helps. Plenty of people are likable, fortunately including the protagonist, Tanikaze. We also discover that the show is more than willing to kill main characters, blow up planets and cause the deaths of thousands as a side-effect of the laws of physics.
Mankind is in danger of extinction, you see. A thousand years ago, space monsters called Gauna destroyed the Earth and now they're threatening the colony ships that escaped. The Sidonia is one of those and possibly the last one, since nothing is known of the fate of the others. Half a million people. If a Gauna gets through, they'll all die.
Furthermore, the show's playing all this straight. Theoretically it's another mecha show with heroes piloting giant robots to fight space battles, but you hardly notice. It's up to its elbows in hard physics, genetic engineering and realistic space travel. Fly too fast away from a battle and you won't have enough fuel to get back. G-force, power, oxygen and even simple inertia can all kill you. The Sidonia's leaders' calculations are, to put it mildly, cold-blooded. It's possible to do evasive maneuvers with the Sidonia world-ship itself, but its artificial gravity can only compensate for 1G's worth of acceleration and so doing this might kill tens of thousands of people who aren't holding on to anything and so will get thrown off the equivalent of a skyscraper.
There are also more colourful worldbuilding details, like clone families, mask-wearing albino immortals and a talking bear. The Sidonia itself is great to look at too. Imagine a slum that's been bolted together into a mile-tall tower. Okay, that's an exaggeration. Most of it isn't slum-like, but it's still both spectacular SF design and a city that's been standing there for centuries.
Some of the show's horror is loud and thought-provoking, e.g. certain shocking aspects of the Gauna. Other horrors are left as Easter Eggs for the thoughtful viewer, so for instance mankind doesn't have enough food. They've updated themselves to be able to photosynthesise (although the only green thing about them is, occasionally, their hair), but in addition people near the end of their lives are expected to go to the "biothermal reactors". Is that really a reactor, or is it something else? They don't even wait until you're dead first.
It turns into a strong show. I'm looking forward to season two. Also, encouragingly, the original manga is now complete (15 volumes, 2009-2015) so there's a good chance that the anime adaptation will get to the end of it.
The politics is interesting. There are idiot peace demonstrators who think the Gauna are only attacking because the Sidonia carries anti-Gauna weapons. If mankind disarmed, no one would even look their way and they'd be safe! These people are portrayed as annoying, stupid sheep who never defend their beliefs intellectually and instead just shout at you on the streets as if they're peddling religion. You have no sympathy for them at all... but as it happens they might, perhaps, be right. The Sidonia's captain is a military dictator (albeit theoretically benevolent) who lets no one sway her questionable decisions.
Great opening theme, by the way. It's riffing off bombastic, chilling militarism, but in a way that's also cool.
It's got me hooked. I'd recommend this. Expect to find the early episodes a bit of a slog, but it'll soon start getting good. It's a cold-eyed, realistic look at a situation that could easily have been played for cliche but is instead being done for real. In practice, what would happen if you sent rookie trainees out to fight planet-killer space monsters? Bingo. Occasionally there's frustrating stupidity from certain people or groups on the Sidonia, but that's hardly unrealistic. The CGI animation is clearly a problem, but I got used to it. It's sort of adequate in a stylised mask sort of way for the humans and gorgeous for everything else. I'm glad I gave the show another chance. Next up: season two.