At the time of writing this review there are three other reviews, none of which are positive, which I find really surprising. The film is quite low budget (I watched the credits to the end expecting that it was made in conjunction with film 4, but its actually the Irish film board) but probably benefits from that. The acting is very good and the cinematography is excellent. James Nesbitt gives a very good performance and its enjoyable to see him in something other than his cheeky chappie irishman mode.
The entire film has an eerie foreboding feel to it, suiting the subject matter. Most of the location is on a run-down housing estate in Scotland and the feel and characters are entirely accurate.
Criticisms? The special effects are a bit naff and Karen Gillen's name is quoted on the advertising blurbs where, in fact, she has a very minor role.
In summary, I wouldn't go out and buy it, and I probably wouldn't watch it again in a hurry, but its a decent enough movie for a rental.