The general rule of thumb in life is if you enjoyed your school years, then you were probably doing something wrong. After all it should be a time of frustration; bewilderment; mega-strops; and for the full experience, a bit of bullying. Ah happy days.

For those attending the college featured in F however, the only lesson that they should really be learning is that of staying alive. Unfortunately for them, that one isn’t on the curriculum.

After being attacked by a pupil in class, Mr Anderson (David Schofield) has lost his teaching mojo. Even a year after the attack, he’s a former shell of his previous teaching self. As is often the case, the one thing pupils are consistently good at is sensing weakness in a teacher. With none of his pupils showing him any respect, Anderson is mostly ignored in his own classroom.

Even his own daughter Kate (Eliza Bennett), who is also one of his pupils, has lost all interest in him. In short, Anderson is a broken man.

One evening, when most of the pupils have obviously gone home, the school is occupied by a few members of staff including the librarian, head teacher and security. Anderson is also there, keeping his own daughter in detention for behaving badly.

Lurking in the shadows however are a group of silent, faceless youths, who are dead intent on teaching those still on school grounds a severe lesson of their own.

Really? Is that the best you can do? It would be more threatening if you came at me with a Gillette Venus.

For the last few years, Brit Johannes Roberts has been attempting to carve out a career as a director of horror. It’s fair to say that he hasn’t exactly mastered the genre yet, and F is no exception.

It’s clear to see what he has attempted to do here: to tap into the fear that people have for youths wearing hoodies. For many, there’s nothing scarier, except perhaps a pack of teens on the back of the bus singing Glee tunes out loud. Sadly the result here is a curious mix of Grange Hill and horror, resulting in a mutant version of Please Sir Scream!

What he does manages to achieve is a sense of foreboding within the school. Let’s face it, they’re scary enough places during the day, so it wouldn’t take much to make them feel more menacing after dark.

His biggest failure, however, is in how he presents his foes. Not only in terms of the number of them – no more than four – but also in their look. Yes they’re wearing hoodies, but no matter how close the camera gets to them, you never see their faces. Not only do they appear as if they should be enemies in a dodgy Doctor Who episode, they’re just as threatening.

On top of that, they don’t say a word. They bound about the place like ninja kangaroos. The problem is that as they parkour all over the school, they look more graceful than dangerous. It would be no surprise to learn that their day jobs were performing at the Cirque du Soleil.

It’s obvious that Roberts didn’t go to a comprehensive; no student or staff member would ever consider being approached with silence by a youth threatening. Throw in a few choice four letter words however and you have yourself a different story.

Give him a little credit though; there are parts of the film where he could have easily thrown up a more obvious resolution to a scene, and yet his characters, particularly Anderson, have a pleasing ambiguity to their actions.

Fans of horror will be disgusted to have this associated with their much-loved genre; it’s obviously low budget and does the best it can, just don’t expect any real scares. It works slightly better as a thriller though, so is certainly deserving of a C+ for effort.