Lingotopia [Kickstarter] looks pretty interesting, a language learning game about being lost in a city. It's on Kickstarter and it's fully funded with Linux support confirmed.
The goal was to reach £8,782 in funding, with £8,963 now gathered so hopefully that's enough to ensure the developer can finish it.
You can see an idea of what it's like in this recent developer video:
It's going to be translated to a lot of languages including: Basque, Bengali, Chinese (Mandarin), Croatian, Czech, Danish, Dutch, Esperanto, Estonian, Finnish, French, German, Greek, Hindi, Hungarian, Icelandic, Indonesian, Italian, Japanese, Latvian, Lithuanian, Norwegian, Portuguese, Romanian, Russian, Slovak, Spanish, Swedish and Turkish.
Might be a nice way for me to learn Finnish to talk to our Friday livestreamer in his native tongue. I like the way it's presented too, with you being able to click on objects in the environment, to learn the word. When you're in a conversation, words you've learned will show up in a different colour, allowing you to hover over for the correct word.
There's also a demo on itch.io if you want to give it a quick blast.