I've read a few reviews while watching the show and most of them weren't very favorable. They were saying it was either "too short or rushed" and/or a "copy" of Chaos;head. I'd like to share my views.
I really enjoyed the anime despite what the reviews said and gave it a 10/10 (the OVA is a different story) as well as putting it on my top 5 favorite animes. I loved pretty much everything about it, the characters, the Red Night dimension, THE SOUNDTRACK!!!!! Organ played at its best in this anime! I can't get enough of these. Those of you who've watched it will reconginze my current avatar as Liselotte Werckmeister from the same show who's my favorite character from that show!
Anyways I want to discuss why I still think this anime is good despite having only 12 main episodes. For me having short animes with well thought-out plots and characters are far more important than trying to extend it out. (Otherwise we'd get a lot of DragonBalls, One Pieces, and Bleaches, you get the idea) And it does this well. While it would be great to have another season we'll just have to settle for this. Thou in the Visual Novel I heard it expands further than the anime.
And the characters while they have a similar "feel" to the chaos;head characters I feel these animes are pretty different. 11 Eyes has a different overall atmosphere with the Red Night compared with the delusions experienced in chaos;head. Which makes the 2 things vastly different. And the characters from Chaos;Head aren't nearly as likeable as the ones from 11 Eyes. I don't hate a single character from 11 Eyes and that's a fairly rare thing.
Its tough but I try my best not to let reviews and friend's opinions influence my opinion of a certain thing. I'm still suspectable to influence sadly. But I really fought with these reviews in my head.
With this said I don't understand why people think this isn't a very good anime. I'd like to hear some good reasons why people think so.