It has great ideas. Huge, future-crunching ideas, with parallel versions of our heroes fighting in multiple time zones and multiple realities. There's the future, another future, a more distant future, a dreamworld (?) and a version of the present day where everyone's a flickering ghost. We have people turning to sand and Timekeepers from the future who might possibly want to destroy the Earth to save it.
Unfortunately the ideas are crowding out the characters. The show's first half progresses almost entirely by info-dumps and dei ex machina. I loved ep.1. Lots of mind-bending stuff happened. I wanted to see where this was going. Unfortunately it goes to a big ep.2 info-dump, followed by a bunch of gunfights. Bland protagonists fight alternate versions of themselves. For a while, this appears to be the spine of the show. Admittedly we still have children disintegrating into sand, major characters getting killed and possibly the end of time itself. That's good. However it would have been better still had our heroes' plot roles involved investigating the brain-bending stuff and using intelligence. Mysteries are less interesting when they walk up to you all by themselves and vomit everything they know into your face unasked.
The gunfights continue. Apparently the show's based on a series of third-person shooter video games, based on a concept by Gen Urobuchi. That explains the ideas, but I notice that he didn't actually write this anime's script.
The protagonist is Tohru Kazasumi, who's pretty much the definition of the Bland Nice Hero. Does he agree to fight because the world might be destroyed? No, it's because of a little girl! He's a blob of ill-directed emoting.
There's a pink-haired girl who likes him, Kyouka Katagiri. She's lively, although she'd have been better with more to do. (Shooting a machine-gun doesn't count.) She's mostly The Girl, really. She has a brother who's sometimes a cock and sometimes isn't. I quite liked Sidune, though.
The show improves about halfway through. Kazasumi's original world drops out of the picture completely after ep.1, which is a shame because it looked interesting, but we do visit the other universe. It made me wonder how this people from this post-apocalypse rural environment could fight a war on equal terms with the computer-tyrannised subtly dystopian SF future of super-advanced bastards, but hey. Both universes have developed time travel technology, so maybe what we're seeing is the redneck reservation or something. After that, the storyline manages to evolve in a direction that's allowing the characters some independent action, so that's a plus.
The show's second half is okay, but to be honest I found it a bit dangerous to watch. It's soporific. The characters still aren't strong enough to hold my attention very firmly. I had no problem with the storyline by this point, but two episodes back-to-back was my limit if I wasn't to find myself lying on the sofa having a snooze. Ep.11 was a pretty decent finale, but then we have ep.12 and two idiots shooting at each other due to idiocy. (A more nuanced analysis of the situation would be available, though, with poor vs. rich and the former wanting power and being unwilling to wait or be intelligent.)
After the shooting, though, I enjoyed the ending with Purple-Haired Girl and her mysterious naming (eh?), going back to school as in ep.1, the first President of the World and dear old grandad. That was gentler and rather nice.
This isn't a train-wreck show. It's a hair's breadth away from being a good one, in fact. It needed a character-driven storyline, although I think the show also has execution issues. Xi's heroism in ep.8, for instance, fails because she's so machine-like that it doesn't really occur to us to see her as anything but a computer fulfilling its programming. I appreciate the fact that the dead stay dead, though, especially since it would have been easy to reverse everything with cheap timey-wimey. There's understated acknowledgement of the fallen in the gentle extended epilogue of ep.12. I don't hate this show at all and there are things I quite like about it (ideas, potential, willingness to kill regulars), but it's less than the sum of its parts.