To Alex: Yeah, 3 out of 6 choices was in America, but that's what the author knows. This a VERY small amount of places that could inspire an openworld game. If some of them are in America, so what? He still mentioned other places.
To Bored: You know that the Soviet Union is in Eurasia, right? He also mentioned Europe as a whole, and do I even need to explain what Australia is? Where did he mention only the Americas?
To the Author: The only problem I have with the article is the title. "In An Open-World games" is not proper English. You have to use either, "In Open-World games" or "In An Open-World game". One or the other, not part of both.