Not as bad as some of these other reviewers say, I actually found it pretty entertaining. I nearly jumped out of my seat during more than a few parts of the film. I will admit, there are moments when the film is a little slow, but the performances were decent with a special nod to Jeremy Walker who played Marvin. Wow, I can't imagine it's easy to play a mentally challenged person and he did it quite convincingly. Jeremy's performance reminded me of when Leonardo DiCaprio played Arnie in Gilbert Grape. I suggest giving it a watch for sure, you won't be disappointed.
I don't suggest watching it right before you go to bed!