It’s related to a mystery geocache here in Finland (you get a code to solve the coordinates with when you win), but you can play it standalone as well.
The source is on GitLab: Mikko Ahlroth / Flag Quiz · GitLab. It’s written very quickly in quite a hackathon style and in a bout of inspiration, so the code is not clean and docs are missing. But it works.
You can answer in English or Finnish in the game. It works best on devices with a physical keyboard.