Historical context is not enough.
The 2 exceptions are:
1. For historical ducumentation -> a computer game is no historical documentation
2. In a critical context -> not the case here, too
Conclusion, german players would risk to pay a fine or up to 3 years prison downloading the game.
This german law is very clear in what is allowed and what not and it includes any modifications of the swastika and symbols of forbidden organisations (SS, SA, ...), which people can recognize as swastika/symbol modification.
On the other hand, the swastika is one of the oldest symbols of human mankind and it's a shame that the Nazis misused it.
Germany is also not the only country where the swastika is forbidden.
Also, the allies have forbidden it in Germany in 1945.
If you click on the link you get an overview of forbidden symbols:
http://www.rechts-nein-danke.de/kennzeichen.html