I was a bit worried when I saw so many people playing simultaneously because the game is hosted on a 2€ VPS at OVH but it worked great!

Great UI!

Thanks for the feedback

The socket library (Flask SocketIO) works great and has a good documentation.

I used plane distance because it's faster to compute and the accuracy is good enough for this use case.

Regarding the UX I think it's a good idea to make the map take the entire screen.

Thanks for the feedback

It would be nice indeed but the fact that you cannot zoom limits the number of requests to the map tiles provider.