I liked the first season, but I loved this second one. I'll be unhappy if they don't make a third.
It's a cell-shaded CGI anime in a distant SF future (the year 3394). The Earth was destroyed a thousand years ago and now a world-ship called the Sidonia contains the last known survivors of a genetically reengineered human race. We're capable of photosynthesis, building amazing prosthetics and hermaphroditism. (Most people are unisexual, but a hermaphrodite will grow breasts and/or sexual organs to suit the orientation of their chosen sexual partner.)
More importantly, though, we're in danger of extinction. We're at war with aliens called the Gauna. They're Lovecraftian planet-busting abominations, but also they seem interested in us and will mimic us in horrific ways that might, perhaps, make you think about their intentions. Are they trying to be friendly? Slaughtering us by the billions and trying to kill our entire species might not sound friendly, but they're Gauna. Who knows what they think? Do they even have minds? We don't understand their lifecycle or how their bodies work, let alone their psychology.
We've even seen human-Gauna hybrids. They're Godzilla-sized horrors that can blast holes through moons, but they're also... girly. In very different ways. Tsumugi is adorable and the main reason I loved this season so much. I'll be talking about her more in a moment. Benisuzume though is, um, not adorable.
What's cool about this season is its genre cross-fertilisation. On the one hand, it's militaristic hard SF in which the show's most important characters are regularly sent out in one-man fighters against the Gauna and a horrible death can happen without warning to anyone. The Sidonia is a military dictatorship and it's working hard on the revolutionary technologies of a mad scientist who once caused the deaths of almost all humans through over-optimism. (He thought his human-Gauna hybrid was safe. Well, it's a mistake anyone could make. Let's try again!)
Meanwhile the Captain's so determined to wage genocidal war on the Gauna that she seems to regard the extinction of all mankind as an acceptable risk. Oh, and don't threaten her position as ship's captain. Really. Just don't.
The CGI animation also helps with this. Leaving aside the CGI-animated humans (who actually looked okay this year), everything about these visuals is rich in detail and realism. There's something brutal and clinical about 3DCG animation that can be jarring as an insert in hand-drawn animation, but for hard SF like this is a massive asset. It looks gritty. You could climb these ladders and walk down these corridors. Nothing is fantastical or handwaved, with even weird Lovecraftian bizarroids (i.e. Gauna hybrids) giving you an impression of solidity and precision. It's atmospheric. The Sidonia really looks like a world-ship that's been flying for a thousand years. You believe that it needs and has engineers.
At the same time, though, it's cute! At times it's almost playing with harem tropes, despite the anti-romantic setting that's full of spaceships, death and tentacle horror. Tanikaze lived underground all his life and the only person he ever saw down there was his grandfather. Tsumugi looks like one of H.R.Giger's Aliens in a Victorian ballgown, but skyscraper-sized and made of fossilised bleeding flesh. (I also have a theory that her human interface is actually her mobile talking penis.) Izana has no fixed gender. Midorikawa is the commander's aide and might at any point might have to give orders that directly cause the deaths of her friends.
Nonetheless, these people were making me laugh. Tsumugi inside is a lovable, terribly earnest girl and her penis's body language is to die for. (I'm running with that frivolous theory I mentioned.) I adored pretty much everything she said and did. Meanwhile Izana and Midorikawa can be sweet and funny too.
The theme songs aren't as good as Season One's, but they have their charms. The opening theme I quite like, especially "knights, knights, knights of Sidonia, ah, ah". The closing theme is being sung with enough camp over-emoting to make me laugh, while the end of ep.12 returns to the magnificent Season One opening theme. Loved it.
I like the darkness and the themes. There's something genuinely disturbing about the human-Gauna relationship, with the speculations about it all being at root an inability to communicate with aliens minds and for instance SPOILER looking so sad just before being killed. Immortality, cloning and Ochiai's Frankenstein tendencies are all in the mix too.
My only problem with the show is that it leaves you waiting for Season Three, which may or may not happen. I could just read the manga, of course. It doesn't end on a cliffhanger, mind you. A battle has been won. There was victory. However there's been a certain development that will make you want to see what happens next.
I loved it. I particularly loved Tsumugi, but I loved the whole thing. Be warned, though, that the show has an acclimatisation curve. The first episode looked good, but didn't particularly enthuse me. The first few episodes left me cold. I got more enthusiastic about the show over the course of Season One, but I wasn't as big a fan of it as I am of Season Two. I think it's the characters. It takes a while to get over the CGI animation hurdle and I also think they get more engaging over time.
Obviously the way to watch the show is to begin at the start of Season One, though. Maybe I should buy the manga? Apart from anything else, I'm curious about how this story will come across in what must be a very different visual style...