The allegory within the movie.
If you watch this movie as a terror film you will not find anything really remarkable or new. In fact many of the original things of the movie, such as the atmospheres, locations and subtle terrorific mood gets completely nullyfied by the easyness and common grounds of the "easy scare" read: loud noises with no other intention than to disturb you, sudden appartions again just to "scare" you...etc this has been made so many times, in so many pictures that it is no longer scary even.
the interesting, yet alternative view of the movie may come from an almost direct allegory within the narration.
Its about RUSSIA and the past behind it. the totalitarism reflects in the fathers tyranny and cruelty, killing the mother which is the spirit of comradery and family (this is a symptom of what russia is nowadays) and as well killing his own future by killing his own children in the most cruel way (feeding the pigs and drowning) again an image of Russia today, where theres no future.
Its interesting as well the importance of the concept of determinism. characters CANT escape their past, the father/Russia engulf their actions and promotes their auto-destruction. Again, this is very similar of what is happening around Russia these days...
Maybe this appreciation goes way beyong casualty.