Sometimes it's necessary to set aside the subject matter and then you can have a better shot at evaluating the film. It's all just a bit too much and I'm ashamed to say probably about 1hr too long. Still for realism, against Schindler's List this wins hands down... As a movie it's a docu-drama of mammoth proportions.
For Polish people this film will undoubtedly have resonance, but if you have little knowledge of the terrible events that happened to the Jews in Poland, during WW2 by the Germans their allies and Poles, then it's difficult to get a starting point. Nevertheless the film does an admirable job in slowly immersing you into the fear, the lack of trust, the moral ambiguity of individuals and a society that has gone way beyond Orwell's 1984... and what's really shocking ... what's portrayed here isn't half as bad as it really was.
BUT ... That aside ... It's set in the stinking sewers of Lotz where around 20 woman, men and children eat, live, play, fornicate, give birth ... And die.... In the dark, for 2hrs 20mins. Sort of like Das Boot - fear of what's above in the daylight, wondering when it will all end ....