Having watched somewhere in the region of 1500 films over my lifetime, I would say that surprises don't come very often. I didn't hold out much hope for this film with the recent trend towards low-budget films but this truly did convert me. The start of the film was intuitive, relying heavily on atmosphere to set the scene. 5 minutes of zero narrative, yet managing somehow to reel the viewer in with intrigue.
The plot as a whole, some might argue is slightly surreal and, without meaning to spoil it for any potential viewers, maybe even unbelievable, but no-one can argue the power of the acting by these three. Gemma Arterton is a very underrated individual, who I can see has only had pretty decent performances. This one in particular was brilliant and thoroughly entertaining and believable. Both male parts are handled fantastically as well. It reminded me of when I first watched The Blair Witch Project - I wasn't expecting much with three nobody's showing up and the entire plot revolving around them, yet the directors managed to enthrall the audience completely. Because of a shortage of characters, you can bond with them, understand them and follow them. Truly deep.
I recommend this film to anyone who appreciates film - admittedly, its not a Hollywood blockbuster with explosions going off everywhere, but find a similarly powerful film released in the past 6 months I have not.