Canada was my first guess, and I was able to get the rest of the Western hemisphere after that. I'm looking now for Portugal which i think should be pretty obvious, but I must be missing something.
Edit. Also, I was wondering why there was no French Guyana, but being part of France means it's not a separate country. However, in that case France should share a border with Brazil. I wonder what other such quirks are in this map.
In addition to sharing a land border with Brazil and Suriname (via French Guiana), France also shares a land border with the Netherlands… on the island of St Martin/Sint Maarten.
Also, there's a new land border between Canada and Denmark, and not depicted on this map, since the border did not formally come into existence until 2022. https://en.wikipedia.org/wiki/Hans_Island#Resolution
Portugal----Spain-+-----------+-France----[Many ¿7?]≡≡≡≡[Whatever, I give up]
\-Andorra-/
but I can't find it.
I think the map in the main article and the graph in the game ignore exclaves and other weird topological parts of countries, but they may be ignoring or counting them in different ways.
Oh! They included Morocco but not the United Kingdom. an interesting editorial decision.
Anecdote time: A few years ago we made a math exposition and we wanted to show something about the Four Color Theorem. We were advice to not use a real map, because each country has their own claims and somebody somewhere may complain.
I had a different strategy, starting with lots of connections, so I found Russia and China first. Albeit playing with a lot of mistakes.
I just did my first second-hand inference and it was satisfying. Turkey borders Bulgaria and Greece, don't know which is which, but those two both border North Macedonia, which was a correct guess.
Edit. Also, I was wondering why there was no French Guyana, but being part of France means it's not a separate country. However, in that case France should share a border with Brazil. I wonder what other such quirks are in this map.