On the day a new planet is discovered, 17-year-old science genius Rhoda (Marling) causes a car crash that only John (Mapother) survives. Four years later, she's out of prison, living with her parents and brother (Baker, Begerage and Taylor) and working as a cleaner. But when she finally gets up the nerve to apologise to John, she ends up cleaning his house instead. Meanwhile, the new planet is now much closer, and its mirror-image geography has earned it the name Earth 2. Maybe up there she can have a second chance.

The film is clearly a parable about the inner longing we have to correct the past so we can move forward. When Rhoda learns that the population of Earth 2 mirrors our own, she applies to travel there and learn if perhaps their history took another path. Meanwhile, John has been unable to move forward, giving up on his composing career and living in squalor (so Rhoda's cleaning job is no mean feat).

But of course this presents a problem for a film, even one with groovy sci-fi touches: the central characters do little more than mope around as they yearn for something that actually won't fix them. While John thinks that Rhoda might be helping him heal, that's only because he doesn't know who she is. As they grow closer, Rhoda only feels guiltier than ever.

Cleverly, Cahill leaves the science fiction in the background, only reminding us through glimpses of Earth 2 in the night sky as well as the pulsing electronic score. For much of the film, the personal drama is central, anchored by solid performances from Marling and Mapother and a sense of growing intrigue as we wonder how their relationship will turn out once Rhoda reveals her identity. But of course, the growing spectre of this other Earth is always there hovering in the background, and its presence makes the finale both provocative and a little unsatisfying.

Erica (Fuller) cleans her boarding house for free rent, then spends evenings in bars looking for men. She never sees the same guy twice, and seems to take it as a personal insult if anyone tries to talk to her. Then she loses her job and has to find real work, reluctantly befriends the rather odd war veteran Nate (Taylor) and starts to clean up her life and come out of her shell. Meanwhile, hothead rocker Franki (Senter) is unable to get over both a break-up and some bad news. And he blames Erica.

The film opens with a moody musical montage of Erica spending a night trawling through bars and clubs, then falling into bed with three men. It's clear that her nightly sexual encounters are devoid of feeling or enjoyment, and clearly Erica likes it that way. Yet even when we've heard her gruelling back-story and seen glimmers of hope for a positive future, there's the sense that her past is going to catch up with her.

The actors play their roles with such raw honesty that they're not always easy to like. Everyone is rather abrasive, but they're also realistic people struggling to make their way while dragging all kinds of baggage with them. At the centre, Fuller gives us someone to identify with, even in Erica's more extreme moments. Taylor is terrific in an intriguingly layered role as her first real friend. And Senter manages to make Franki surprisingly complex.

Rumley gives the movie a dark, lush tone that continually hints that something's deeply wrong here. As a result, we know Erica won't get away with this careless lifestyle and antisocial behaviour, which gives the film a whiff of uncomfortable moralising. And then there's the elusive storytelling and abruptly disorienting shifts in perspective from Erica to Franki to Nate. So while it's a skilful, startling mash-up of mumblecore and horror, the excessive developments of the final act are perhaps a bit too gruelling.

George (Russo) is floating through life in East London while his girlfriend Sophie (Lovibond) has a great job and ambitions for the future. For some reason, she has entrusted him with a box of cash that they'll use to pay for a dream holiday, but he decides to invest it in a drug deal for a quick profit. Of course, everything goes wrong, mainly because his best pals (Pope and Maskell) take advantage of him. And as a result his relationship with Sophie starts to suffer.

While there's nothing much to the plot or characters, the actors deliver textured, intriguing performances. We never quite get a grip on the interrelationships between the large number of characters, and the narrative lurches from point to point, but everyone on screen, including the smaller side characters, is compelling to watch. And at the centre Russo and Lovibond give us a terrific sense of what makes George and Sophie tick, why they are attracted to each other and why they're struggling now.

At its core, this is a story about how even our most personal decisions affect those around us. And clearly George and Sophie have made some divergent choices over their years as a couple. Now it seems like neither of them is very interested in changing direction, so a clash is inevitable. This is fascinating to watch, but not hugely engaging. We're unable to really sympathise with the pain they (and others) go through, since the script never gives us anything we can identify with.

But even as observers we are drawn into the events as they unfold. These people may be thoughtless jerks most of the time, but they are very human. And while the plot drifts into some contrived story points (who pays for a holiday in cash anymore?) as well as some painfully obvious moralising, at least it offers a glimmer of hope in what's otherwise a rather grim situation.

After hanging out with his lively group of friends, Russell (Cullen) sneaks off to a gay nightclub looking for companionship. He meets Glen (New), and it isn't until the next morning that they begin to get to know each other. Their one-night stand then stretches out over a weekend of alcohol, drugs and parties as they both struggle to cope with how quickly they have developed intense feelings toward each other. Which is a problem since Glen is moving away on Sunday.

Shot guerrilla-style on location in Nottingham, the real settings add to the film's bracing tone, as director Haigh stays close to his actors and captures details and conversations we rarely see on screen. Photographed like a documentary, the clever, intimate camerawork and editing highlight the characters' physicality, both between the couple and in Russell's scenes with his best mate (Race) and also an encounter he has with Glen's chatty friend (Freeman).

The strong connection between Russell and Glen is the heart of the film, and Cullen and New create believable, engaging men who continually reveal layers of complexity, from cheeky humour to brittle self-doubt. Aside from a bit too much inebriated messiness, these are two remarkably well-developed characters, and their interaction cycles through scenes that are hilarious, awkward, intense and powerfully emotional.

Along the way, the script touches on rather a lot of big issues as Russell and Glen casually discuss their lives and, most pointedly, their experiences as gay men. So besides being an involving drama, the film has important things to say about being gay in an often hostile straight society. As Russell observes, he never feels particularly gay when he's alone at home; but when people on the streets, or even his friends and family, look at him or treat him differently, it makes him angry, which in turn makes him feel pathetic. Observations like this one make this film essential viewing for much wider audiences than just gay film festivals.