Lots and lots of spoilers below.
First of all, let me be clear and say that I have not seen the original "Friday the 13th" in over 10 years. It isn't a movie that stayed with me in any way - I've always been a fan of Halloween / Michael Meyers. That said, I think I know what makes a good horror film, and I know that none of those things are in this film.
My first complaint lies in the structure of the story. The first thirty minutes or so of prologue lend nothing but confusion as to where the story is going. When we find out after the first group of murders who has been kept alive and how they are connected to the second story line (Clay's search for his sister), I had spent so much time being repulsed by the group of friends that I really had no emotional stake (re: I couldn't even remember the character's name) in whether the girl lived or died.
My second complaint lies with I expect that there will be the obtuse sex, drinking, and drugs in any "campy" horror film like this, but these first 30 minutes were so packed with inane boobs and weed shots that I was ready to consider this a comedy, not a horror film. I'm not looking for social commentary when I see a slasher film, but all of the references to marijuana seem like they're being made by people who have never even come in contact with it. It's almost like when you're in High School, bragging about how high you got, and the guy you're talking to lies so that he doesn't feel stupid for not partaking in substances like that: "Man, I got SOOOOoooo freaking high last night. What'd you do at the party?" "Oh, uhm, I smoked several weed cigarettes and drank a couple brewskis, then passed out." Apparently, this guy wrote a screenplay for a Friday the 13th "remake".
Lastly, although I could probably keep complaining about this film, Jason is absolutely NOT SCARY in the first half of this movie. By the time we're midway through the second story line (I contend that this movie should have been called: "Friday the 13th: A Bunch of Douche Bags Go Camping, and Jason Voorhees Is Somewhat Involved") there have been so many crappy people on-screen, and they have been killed by Jason in typical Jason style, he just isn't that scary anymore. We know he's there, waiting for the topless girl with fake boobs to swim ashore so he can decapitate her. WE KNOW. This film is neither atmospheric, nor does it even attempt to build tension. It is simply a terrible movie.
Other grievances: The pot-dealing redneck, who is only introduced so that he can be killed and Jason can find his hockey mask (a full HOUR into the film), is the single most disgusting character I've ever seen on-screen. This is not a compliment: just before his "untimely" demise, he talks to a mannequin, and asks the mannequin if she "remembers that night, when (she) took (his) virginity". I would rather be decapitated by Jason than ever hear those words spoken in a film again.
Why is it that every Michael Bay production or direction has to include the blue halo / lens flare around electric lights? I noticed this early on, but at one point later in the film, as a flashlight goes across the screen, there is actually a sound effect applied when the lens flare hits the audience. WHY? How much money did you spend on that? How much time was spent adding that tiny "swoosh" into the soundtrack? God, Michael, get a freaking life - you can't just add things like that and hope that you've produced a good film. You haven't. And you never will.