Sure, this movie is definitely a Halloween clone, but why should that mean it's bad? If Halloween is so good and this movie resembles it, then why not like this one as well? I don't understand why so many people have a problem with that. I mean, Halloween itself is a clone of another movie anyway (Black Christmas). So if you can accept that, then accept this one too.
Out of all the 80's slashers, He Knows You're Alone definitely ranks up there with the best and most underrated. Right from the clever opening sequence (which was later copied for the opening of Scream 2), I was instantly hooked. From there, it develops a quick and simple backstory where we learn that the killer was dumped by his fiancé so she could marry another man. And as a result, a few screws are pulled loose in his head and he begins hacking up a bunch of brides-to-be, which brings us to the main character of the film and her friends who he begins to stalk.
The pacing throughout the film was very well done. It built up a very effect creepy atmosphere that oozed with this sort of quiet dread that can really manage to make you feel uneasy. The characters were actually quite likable here, which is something of a rarity in the slasher genre, and they were very well acted (including Tom Hanks in his very first movie appearance). The great musical score, while it will definitely remind you of the Main Title theme of Halloween, also had it's own unique sound that made it very memorable and haunting. It really helped make the atmosphere even creepier, especially afterwards when you've finished watching the movie and the theme is still stuck in your head. Another major plus involves the killer. We barely get to see him and when we do, we're reduced to only a tight shot on his creepy bulging eyes. And it's pretty refreshing to see a killer's bare face since most slasher maniacs always wear a mask.
So if you're a fan of Halloween or other similar themed horror movies, then I would definitely recommend this one. It's a real shame that this one got overlooked during the whole slasher boom that Halloween started back in the 70's and 80's. It's pretty creepy and well worth watching overall.
