I am genuinely surprised by how entertaining _Killer Sofa_ turned out to be. I’m not sure if I can even label it "good," or suggest everyone should see it. However, if the poster caught your eye and you felt compelled to watch, then you really ought to. It's strange for a film centered around a killer couch, but one of its issues is that it attempts to incorporate too many ideas. You’d assume a simple premise would b…