This film is poor

How do I write this without sounding like I'm one of the dozens of trolls on IMDB?

This film is poor. I don't think it was aimed at me (44, Male) admittedly, but despite that it was still poor.
It's hard to describe it because I'm not even sure it knows what it was trying to be.

I read one description that it's supposed to be sexy, funny, comedy, horror.

Sadly it's not any of those four, I would be happy if it was just one.

Sexy........ To be sexy it needs to be seductive, have an undertones of sex, eroticism, a bit like what they do with vampires (killing that genre) but this has nothing. It's not moody, sexual or anything.
Is sex mentioned? Yes, oh hell yes it's mentioned over and over and over again, but in a supposedly funny way.

Traditionally there is the romance sub-plot of two people fancying each other to keep you interested. This didn't even have that.

Funny and comedy....... Really? The comedy in this is definately not aimed at me. The nearest I could compare it to would be the UK series The Inbetweeners. Young lads wanting to shag but not being any good at getting any. It's a very old idea, we had it with that film, American Pie, Screwballs, Porky's, The Last American Virgin and so forth.
This is very traditional UK attempt at trying to create British characters a bit iike the American Pie kind of guys. Why we have to do it I don't know as it never works. The AP guys are idiots but funny. The UK counterparts are idiots and... well just idiots!

Actor Timothy Spall is a really good actor and he can do comedy well, but he does need a decent script to work with and he didn't have it in this film.

Horror....... Yeah right! I would happily let an 8 or 9 year old watch this as ar as the horror content goes. It's not scary, it's not tense, it's not gory, it's nothing! You see more blod and grizzly looking stuff on Casualty or Grey's Anatomy. If it wasn't for the never ending tedious sexual references I would give this a 13 certificate. The horror isn't enough to even give it a pg-13.

As I say this film is a mess of a film because it doesn't know what it is trying to be IMO.

It's not a horror film, it's not a comedy and it certainly is not a spoof or a pardody of that genre or a show like Teen Wolf.
I would say don't waste your money seeing it at the cinema, don't waste your money buying the DVD or Blue Ray, wait for it to show up free on TV and watch it then.