Monster Hunter : World, the latest iteration of the Monster Hunter games, has been making the rounds ever since it came to the consoles. The console version was received so well, Capcom went on to score 8 million sales on both the PlayStation 4 and the Xbox One. The PC version is performing well, with an estimate of 2 million sales on Steam.
The official Steam Spy page estimates the sales to be somewhere between 2 million copies and 5 million copies on Steam. Thanks to a few changes made by Valve a few months back, estimating the exact sales is tough, but a ResetEra discussion thread estimates the number of copies sold to be closer to 2 million than it is to 5 million.
This does make Monster Hunter : World the highest grossing Japanese title to enter the market, scoring well over 10 million sales on all platforms. However, Capcom has not issued an official statement to substantiate these claims.
The game also has seen a peak player count of 329k players, with 204k concurrent players playing the game at the time of writing this article.