A topic I’ve become fascinated with in the past is games that are available in neither English nor Japanese (especially for non-PC platforms), since most games released on consoles are available in one of those two languages.
There’s a lot of games that are based on European properties, like gameshows and children’s books.
Indian (Samurai was an official regional NES), Chinese (not just iQue), Taiwanese (eg. recently dumped hybrid MSX/Sega Master System games), Chilean (such as educational games about Easter Island), Brazilian Portuguese (big Master System scene), Spanish and Dutch (big MSX scenes; Philips was Dutch).
I’d be surprised if there was a language that had no native video games.