This independent German film is based on a novel - and follows a twisting thriller trope, with plenty of comedy too. A bit like UK TV series New Tricks or any other about art forgeries.
It is also an identity swap drama/comedy and original in that, however unbelievable. I doubt this actually happened. Though some Allies spies dressed as Nazis and some Nazis dressed as Allies troops - in the fog of war and invasion.
Best to focus on the drama and comedy, not the details here or the trueness to life - the concentration camp inmates look far too well-fed and healthy, for a start.
A nice documentary on the making on the EXTRAS which is worth a watch - it points out most WWII films about Jews show them being saves. Here the Jew saves himself.
I enjoyed it,. 4 stars.