After a breakup, Tammi (Burley) goes on holiday to Spain with party-loving friends Lisa and Kim (Krekin and Winstone). They meet three fellow Brits, the cute Josh (Morris), sexy Marcus (Taylor) and cool Bluey (Burke), who invite them back to the luxury yacht they work on. The boss is away, and Josh's big brother Sean (Boulter) is manning the ship, as it were. So they decide to take an afternoon cruise and enjoy some alcohol, drugs and sex. But the combination goes horribly wrong, and they can't agree about what to do next.

The title refers to a violent punch given during sex, and the resulting calamity leads to a taut morality tale as these morally murky young people come to blows about what's the right thing to do. These scenes are played out with such realism that the more we get to know about them, the less we like them. Only one remains relatively out of the fray, and we know what that means in a genre film like this.

But as this drama cranks up, the suspense evaporates. The fresh cast is good, throwing themselves into the physicality of the roles in every imaginable way. Their spark of energy is what keeps us watching, even as things get increasingly boneheaded and gut-wrenchingly grisly. Ill-judged actions, bad decisions and horrific repercussions are the order of play here, and the actors all maintain a genuine sense of insecurity and fear masked by bravado.

But frankly, these stupid people are so clearly stuck in a dopey horror movie that it's impossible to sympathise with them. Their decisions defy logic, and even the intriguing boys-vs-girls set-up never develops into anything beneath the surface. Just as we begin to wonder what we might do in the same situation, the group launches into an orgy of infighting, betrayal and murder. And while it is seriously nasty and often quite head-spinning, we sit back and hope that they'll just kill each other off and leave the world a better place.

Hudson (Perry) is a screenwriter who, after smoking too much weed, feels disconnected with everything around him. His writing partner (Pollak) is annoyed that he spends all his time just watching the Golf Channel ("It's green and people are whispering"). Not to mention the compulsive kleptomania. Then Hudson meets Sarah (Collins), a studio development officer who's just offbeat enough to break through his numbness. Meanwhile, a series of therapists aren't helping, especially when one of them (Steenburgen) becomes obsessed with him. It's going to take a cold, hard shock to snap him out of this.

Perry clearly relishes having an intriguing character like Hudson to sink his acting teeth into. Besides his work on The West Wing and Studio 60, he's never had very challenging roles, and this one certainly crushes all preconceptions. He really catches Hudson's darkly comedic inner turmoil, even if writer-director Goldberg never quite manages to fully express his condition on screen. We only feel it through Perry's performance.

And around him, the solid supporting cast also does as much as they can with their thinly defined characters. The film really comes to life through the quirky and often completely nuts relationship between Hudson and Sarah. They make a terrific on-screen couple, so when the script becomes a series of episodic, disconnected sequences it's more than a little frustrating. The whole depersonalisation issue, which could have lent itself to a biting satirical study of modern society, gives way to a silly, repetitive romance, complete with tired cliches and inexplicable plot turns.

In the end the film turns cautionary and sentimental, avoiding the sharp issues for more mushy melodrama and zany sight gags. At least the people who come in and out of Hudson's life are packed with personalities that add interest even when the plot starts to stall. And in the middle of it all, Perry shows what real potential he has as an actor. If only someone would give him more interesting roles like this one.

Son Hayes (Shannon) isn't surprised when his wife (Pannell) walks out. He's not the easiest person to live with, but soon his loser brothers move in: Boy (Ligon) lives in his van, while Kid (Jacobs) stays in a tent in the yard. And we soon discover their problem when they attend the funeral of their drunken father, who ditched them years ago, then cleaned up his life, remarried and fathered four more boys (Abbott, Smith, Provence and Rhodes) who live across town. And a nasty feud's growing between them.

Filmmaker Nichols catches the setting vividly; we can feel the Southern gothic presence of producer David Gordon Green, as much of the film feels like it lives under the skin of the characters. The story is told as a series of raw, earthy and muted black-out scenes that are assembled slowly and surely, kind of like the lives these people live. And the bitterness that emerges between the two sets of brothers is seriously terrifying, simply because it feels so inexorable.

The acting is bone-dry and startlingly genuine. The superb Shannon holds the film together as the only brother eventually able to look at things with any perspective. He's plays Son as an intelligent man who has never developed his intellect. And he makes a terrific team with Ligon and Jacobs, as two more guys whose lives have been stunted; in different circumstances they would be pillars of their community, but here they feel like losers.

The events are approached with such raw, measured honesty that it's difficult to know what the filmmaker is trying to tell us. Is it about how the sins of the father wreak havoc on the next generation? Perhaps it's an examination of a grisly situation in which there aren't any real villains. Or maybe it's a treatise on the futility and unstoppability of vengeance. Whatever, this is haunting, horrifying and fiercely emotional filmmaking. Berlin/London

Mike and Sheryl (Randall and Brown) are on a two-day hike in the Virginia wilderness. Despite a warning from the ranger (Bressler), they take a scenic route, where they have an ugly encounter with three local rednecks (Morgan, Leshner and McGee), but get away for a sexy night in their tent. The next day, however, Mike awakes to find that Sheryl's been abducted by a religious nutcase (Broderick), her husband (Searcy) and her deformed brother (Rosemann). And if Mike and Sheryl don't go along with their crazy plan, it's not going to be pretty.

Filmmakers Giglio and Kay are working in the torture porn genre here, but they invest just enough into the set-up and characters to transcend the mindless horror of recent films. Yes, there are some extremely grisly moments, but moral issues and twisted dilemmas are also woven in. And they continually subvert expectations with a plot that goes into some seriously nightmarish directions. In addition, the characters all have lively personalities that add some real spark when they clash.

Randall and Brown are terrific as the central duo, sardonic and practical, respectively, and just sympathetic enough that we actually care what happens to them. Especially when things start turning brutal. Meanwhile, Broderick chomps on the scenery with shameless glee, never winking at the camera and becoming one of the most unusually terrifying horror villains in ages.

That said, this is still a pretty grim movie, with excessive gore and sequences that are contrived and preachy. Some of the acting feels amateurish and silly, while the story feels made up as it goes along, barely connecting the dots at all. And all of the cod-fundamentalism gets tedious after a while (kidnapping, violence and murder are fine as long as you don't swear!). In other words, the film is cheap and nasty. But by keeping their tongues firmly in their cheeks, the cast and crew make sure it's also pretty hilarious.