Not very good
I understand the importance of the film and its historic value, but cinematically speaking it is not a very good film.
Too much exploitation and coarse emphasis on the deformity, extremely simplistic and childish view on morality and humanity, a script with many flaws in favor of the action (for example, it was funny how she tried to poison him immediately after the wedding, and again immediately after the first failed attempt, while all the others were supposedly ignorant). The ending, too much, just to shock and preach.
This is not nit-picking. There are some masterpieces from that era, even by todays standards. I have to say though it was a quite enjoyable film.