What makes it different from others?

I saw this movie before reading any reviews, and I thought it was very funny. I was very surprised to see the overwhelmingly negative reviews this film received from critics.

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 turns out to be a little better than the average. Starting from a romantic formula often seen in the cinema, it ends in the most predictable (and somewhat bland) way.