hehe, well this seems to be my 'gory pleasure' of the new season.

Loved the use of sfx in the first sequence, the echoing, the lack of voices and sounds, very well done. The sounds/voices those monsters make... man I'm gonna have nightmares about those fuckers... However it the voices afterwards did sound very 'staticy' as Ryll mentioned above... hope that won't be the case next time, it was really annoying... Music was pleasantly good.

I can hear the scribble of thousands of pens belonging to perverted doujinshi artists already working furiously on some doujin porn about Shindou and his sister... and yeah, that's some fugly ass hair on that guy.

A murder involving hundreds of people and Shindou is talking about the killer? Yeah, one guy killed all those people, right. Possible oversight in the translation?

Kunikida cracks me up. Jumps out fast into my 'fave character' race. Nice, unique sounding voice too. "And don't forget the shotguns!" Damn straight!

as for VAs: Shindou = Shinn Asuka (the laugh gave it away)
Saya and Shindou's friends aren't too familair to me, but the friend has a very familair sounding voice... can't place where from though
that weird girl who licks Shindou's face = Rin Toshaka (F/SN, watched an ep right before this show)

Contrast between humor and gore is actually pretty good in this first episode. I didn't feel like either elements went 'over the top' in being used. One thing that sorta distressed me was the somewhat shoddy animation in parts of the encounter at the end with the Human Face monsters.
All in all though a very promising looking series. Oh, and Shindou looks to be holding a nice sized broad sword in the ED = )