The Sims series is general fare in most places, as popular with teenagers as it is with older folks. Oh, except in Russia, where fear of the gays and their gay propoganda has the game restricted.
Russia being Russia, there's a law - which has made international headlines over the last year - that considers any media containing homosexuality to be a form of propaganda, and aims to "protect children from information advocating for a denial of traditional family values".
So The Sims 4 - which, with its freestyle playing options, allows for gay relationships - has been slapped with an adults-only rating. For reference, in most other markets it's available for young teens, while as Ars Technica points out, in Germany you can buy it if you're six.
It won't stop the game being sold, but it will be a pain for Russian fans, and no doubt for EA as well, since Russia is such a big PC gaming market.