You can't have "mostly" free expression. It's either abridged or it isn't. Germany censors harmless digital art that the government deems inappropriate for adults to be able to see. It's a classic slippery slope (modern Germans defending their government's censorship and lack of free expression will usually cite Hitler/racist stuff, but that's not all that's banned).

It doesn't really matter what the constitution says, if in practice you don't have those rights. It's sort of like how the 2A in the USA says that the people have the right to keep and bear arms, but I don't suggest attempting to exercise that right in Central Park, because you don't actually have it. Same goes for free expression in Germany.

From https://scholarsbank.uoregon.edu/xmlui/handle/1794/19123 :

> Germany is one of the strictest censors of violence among the world’s video game consumers. Due to its history and a cohesive national opinion, the legislature limits content severely, much more severely than the surrounding European nations. This results in international developers choosing not to market to Germany, creating censored titles specifically for the German market, or finding themselves on a list of banned titles illegal to buy or sell.

[1]: there's also no indication that racist publications were responsible for WW2 (versus, say, Hitler himself), making this censorship-for-censorship's sake. Many other countries do not prohibit racist literature and have not committed a holocaust. So, of course, they banned violent video games too, because those don't cause violence either.