Being a russian I want to say that many russians are offended by this movie. Though it has some real stuff in it, many things are stupid and even abusive. Like russian soldiers being brought to the front line in the sealed cars with barred windows like criminals or some sort of cattle. Or soviet officers only drinking vodka and shouting around. How did they win the war only doing that?
A Hollywood director sitting in his cozy chair can't even imagine what was that war like. And I think he doesn't want to. In Russia, we've been taught a little about the war. Stalingrad had a long battle in the middle of a coldest winter of the century. People were starving and freezing to death. And a red-cheeked boy walking around in shorts (at -40!!!) looks like a stupid joke. So does a soldier woman with long painted nails putting on her make-up before the attack. So does the slogan in Russian on the wall "Long live the socialism". Does the director really think the Russians were such maniacs to write on the walls how they loved the socialism? "We will win!" That's a real slogan from that time.
This movie has a lot more inaccuracies but I can't and don't want to enumerate them all. Just... the director should be embarrassed of his work.