I think it was the whole comedy/thriller balance that didn’t work for me.
In order to be gripped, you have to have peril and danger, a genuine sense of dread. But when even after discovering a dead body in her bed, the main character is quipping and making jokes, the whole jeopardy seems, well, laughable.
I actually think Kaley Cuoco is a good comedy actress and in the hands of another, the character could have been unbelievably annoying, still I wasn’t all that bothered about finding out what happened.