From the various bio's I've read and associated papers from the Red Army, they really aren't over stating it. Keep in mind the Nazi's were involved in kristallnacht, the removal of socialist organisations within Germany, Treblinka, other eugenic programs, Mengele, Siege of Stalingrad, forced vote with austria and everything else.

And yes other regimes did horrible things too, not every member of the Nazi party took part in the varying atrocities and there certainly German soldiers who behaved with valour and honour in the war. But in terms of war games and other media they aren't overstating the 'evil' except where they are getting silly.