The language use was interesting. A handful of scenes in pure German, with subtitles. Songs in German. The majority of the film in what amounted to 'Allo 'Allo! German: English with a German accent, and commonly understood German words mixed in. Street signs, shops and such all in German, but a diary in English. Narrator and three principal actors from Canada, Australia and England, the rest Germans. So basically, as German as they could get for the average English audience.
The Parental Guidance rating is certainly appropriate - there's some violent death in it. But I think it's got a few good teaching points, too. For example, understanding why people might join the NSDAP (Nazi Party) even if they hated the ideology, and the risks of standing out or speaking out in an authoritarian regime. Painting war in shades of black and white is deceptively easy to do.