The setting for "Night Head Genesis" was good, and it began brilliantly, but the problem I saw in most of the episodes was that the plot didn't feel steady enough; perhaps it was meant to make the viewer ponder about what just happened, and what motivated a certain action or result, but to me it felt like they randomly grabbed things from here and there and ended with a conclusion that seemed a little odd and out there. In short, the plot wasn't as straightforward as I would have liked. "Plot holes" was what came to mind, because the flow just didn't feel consistent enough.
I absolutely loved the art. The characters were pretty to look at, as was the scenery. And although some of the animation (mainly the scenes with cars) stood out, it was a steady flow of beauty. Another thing that I fell totally in love with was the music! Ending themes I didn't so much care for, but the beginning theme and overall soundtrack of the episodes were amazing.
The only thing that really bugged me besides the troubles with the plot was the voice acting. Mostly it was good, but especially Naoya's "screaming" was something that kept me frowning - or cracking up, which probably wasn't what they aimed for. It just didn't sound real (it was very un-cool in a way).
There wasn't all that much character development. In the case of Naoto there was some, because he had to come to terms with the darker side of his power, but either the story failed, or I didn't see the whole transition moving flawlessly. Naoto's reactions to a lot of things, especially as a kid, kept me shaking my head, but maybe that was just his bigheaded nature, who knows.
All in all I enjoyed this series. It could be better, and I wished it would have been longer because the story in the last two episodes was the best of them all!
"Night Head Genesis" had some brilliant stuff in it, lovely relationship between two brothers, and although some of the characters and their motivation never really pulled through... this is certainly worth another watch.