Load of rubbish!!

It's funny, it's tense, it features two great performances from two actors and the director expertly creates a web of odd tension where you actually don't know what is happening for the majority of the run time.

The movie's not perfect, but it sticks the landing of its message. It was engaging - thrilling at times - and I personally thought it was a great time.

While it doesn't offer any answers, it both thrills and makes you think.