where i think all these new slasher films fail...
Yeah, i too wasted $7 dollars in this dvd. Some points i've noticed that keep repeteadly being done in most 'modern' horror films (specially slashers):
1. Almost every new film looks extremely sharp / clean... Seems like all are being made in digital video or with similar techniques (i miss grainy 16 mm old independent films or even 35 mm old ones, which look raw and somehow add a really creepy feeling)
2. Everyone is pretty... even killers, violators, etc. Almost all these young actors / actresses don't show any personality at all... they all seem 'arranged' by plastic surgeons... Take a look to old Friday the 13th movie series, or rape & revenge flicks like Last House on the Left, I Spit on your Corpse, etc., and learn! Those look alot more like 'real' people!
3. That stupid video-clip editing. This particular movie (Knock Knock), has some really decent gore, but every killing is wasted with that 'oh i'm really modern & cool!' style of editing (so used nowadays)... Good gore looks better when shown directly (short or long shots), instead of this MTVish crappy editing (See old Dario Argento or Lucio Fulci films for example).
4. All the common restraints and poor qualities of most modern filmakers: bad script, bad photography, bad acting, bad directing, etc. I know that many 'so bad its good' movies lack of these, that's why i'm putting these at the end. The first 3 points are for me the worse, 'cause they've become a cliche trademark of most of the modern horror flicks. Sometimes one good thing in this last aspect can save a whole movie (bad movie but with good actors, bad movie but nice photography, etc.). Oh, also a little personality or originality always helps!
This is only a personal opinion, i think anyone could make their own conclusions or points where you think new horror films are failing.