Premise was weak, characters were all unlikable, style got repetitive with too much imagined or unnecessary violence, not enough comedic relief to make the plot work. The dialog was so cringeworthy, I couldn't make it through a whole exchange between any of the characters without feeling like something was being taken from me. Why are these people not more afraid of her? How does she make a keep acquaintances? Why is she not in a psychiatric ward under lock and key or prison if she really can't control herself? How does putting that amount of makeup on in the morning not put her into a homicidal rage every morning? The movie will entice you to ask alot of questions, but none about the plot, which was so obvious it smacks you in the face with exposition every time she takes a break from virtually stabbing someone in the neck.
On a side note, did Kate Beckinsale have some extreme plastic surgery or was that some kind of special effects makeup? I honestly thought she was some model-turned-actress in her late 30s trying to find a vehicle before her appeal faded; completely unrecognizable as herself. I don't think she was ever really great in anything, but this is definitely not her best work.
I gave it two stars because as bad as it was, I've seen much worse. Low side of mediocre seems fair.