The first three minutes of Knock, Knock, which basically revolve around someone playing ding-dong-ditch and following up this cheesy, childish little stunt by punching through what looks like a solid mahogany door leave me nonplussed at best.
Sad to say, this low-budget shitstravaganza isn't going to manage to follow up any better.
The plot is rather simple enough--someone's going around killing popular kids at a high school and leaving their bodies scattered around like so many Twinkie wrappers. Like the title suggests, he'll be doing plenty of knocking, but if you tell him you can't come in, he'll just come right through anyway.
If it sounds like you've seen it already, then you won't be saddened at all to discover that, yes, indeed, you have. This is a relic beyond relics--they were doing this kind of crap back in the eighties, for crying out loud, and it's no more satisfying now than it was then. It's an extra sad blow, making the guy nobody sees or hears anything out of until the last fifteen mintues or so, like they just thought "Well, we can't very well make the possibly mildly retarded janitor the killer, so let's just make him a huge red herring instead!" and so tacked on one guy extra to fill out the killer role.
This isn't just sloppy filmmaking, this is balls-out LAZY filmmaking.
And yes, I know this film probably had a shooting budget better suited to buying groceries than actual moviemaking, but surely we can get a killer a better mask than some stupid papier-mache setup. Even the original Jason Voorhees had a bag on his head; this halfwit's wandering around with something from arts and crafts on his face.
By about the halfway point I began to wonder why he even bothered wearing a mask. Several of his victims didn't actually see him coming, and those that did didn't see him coming didn't last long enough to have much of a reaction to him.
The ending introduces the killer, without so much as foreshadowing, and makes him some kind of superhuman juggernaut who can take half a dozen rounds to the chest as well, so it's cheesy as all hell.
The special features include four different featurettes.
All in all, to play with the movie's own joke: Knock, Knock. Who's there? One star, bitches. This thing sucks sour frog ass. This warmed-over slop is just plain pointless. They're not doing anything new here, nor are they doing anything good with what's already been done. Definitely not one to waste any time on.