Wow, this is something special. I don't think I've enjoyed a single episode of anime this much in a long time. It's really that good.
The writing and presentation is just goofy enough to make the bizarre premise work. Yeah, it's ridiculous, but I was too busy laughing to care. And yet, even the dramatic moments felt genuine. I couldn't imagine trying to explain how it works - it just does.
On the production side, the animation is top notch. I was particularly impressed by the quality of the OP - both animation and music. The ED really floored me, though. Maybe I'm just a big softie, but that minute and a half of music and animation - which is an afterthought most of the time - told me everything I need to know about the show.