Yeah, link got broken. Should work now. Sorry. I'm still updating this stuff and the English translation is a bit wonky.

Video games are also art. The concept is an open one. One court examined Medal of Honor under the concept of art.

Art is indeed the most important aspect to use Nazi symbols legally in games. There is also something called "similar means" written directly in the social adequacy clause. That refers to acts "approved by the general public and are therefore wholly unsuspicious in social life because they are in the context of social freedom of action" in accordance to a ruling of a high court.

More important than all these aspects is the that the ban must be interpreted restrictively, also in accordance to high court rulings. If the depiction opposed the ideology, then it's also legal to use the symbols, simply said.

It's pretty complicated and goes further than the art argument. It's misleading to assume that movies always or just get away because they are art; they are simply most often not suspicious for the rating agency (the FSK), and the general public.

The USK for games has its issues because of a almost 20 year old local court ruling. That's not binding but it's the current situation more or less.