Ray Wise is such an extraordinary actor he can convince us his character is an actual person despite his super-duper famous face and the awful clichéd lines he's got in the film, while Adam Green is so bad as an actor he convinces us he cannot interpret his own actual self. These contradictions compromise the whole movie's verisimilitude and fun. Besides, it's Green being Green: fake, lame, unscary, and narcissistic.
I actually kind of really liked this. If the story being told wasn't so diluted with self promotion and "do you believe me" being said every two seconds, I think this would have made a really great horror film. I'm no pro, but I think there were a few predictable scary moments and a GIANT missed opportunity (by not exploring the Marrow further). Still, not so bad.