It'd be fun to see this for the whole world. It would also make it easy to compute the answers to common quiz questions involving doubly landlocked countries, countries with most borders, etc.
Curiously that doesn't seem to be accessible without logging in to Twitter, and I'm not inclined to do so at the moment; do you have another link to the game?
Did you open it in a tab that was not immediately made active?
There seems to be some sort of issue with Twitter whereby the javascript to fetch/render the tweet doesn't fire if you open it in a background tab and then visit the tab.
Refreshing the page causes the javascript to correctly fire and the tweet is displayed. This is due to Twitter no longer pre-rendering the page server side, its all done client side.
Also makes it impossible to use Twitter from a browser with javascript disabled.
I think Twitter might be throttling anonymous/not logged in users. On desktop, where I'm logged in I've never had an issue with retrieving content, on mobile, where I'm not, no matter the browser, it's hit or miss (I'd estimate around 30% of the time I need to refresh)