Xbox One didn’t have a traditional blockbuster exclusive at the end of last year, but I’m having a difficult time seeing how that matters when the one game it did publish just surpassed 3 million copies sold since December 12. PlayerUnknown’s Battlegrounds continues its reign as a sales behemoth and as a smart move for Microsoft. The company released the last-player-standing battle royale shooter for developer PUBG Corp as part of the Game Preview program for unfinished projects. Players can spend $30 to participate in this early testing, and a lot of people have done exactly that.

In a blog post on the Xbox Wire news website, Microsoft’s games marketing boss Aaron Greenberg was almost apologetic about PUBG’s success on Xbox One. The game has had a rough launch. In certain circumstances, the shooter can struggle to maintain an acceptable framerate — that’s especially true on the original Xbox One hardware as opposed to the Xbox One X. Microsoft was sure to point out the frequency of updates from PUBG Corp since December 12, and it promised that more updates are in the works.

“The team at PUBG Corp. is determined to continue to improve the in-game experience for PUBG’s growing and active community,” said Greenberg. “[The studio has] already released four updates since the game’s launch in Xbox Game Preview on December 12. You’ll continue to see regular updates roll out for PUBG on Xbox One such as this week’s addition of first-person support for solo, duo, and squads gameplay and the team is just getting started, with more updates planned that include additional game optimization and the new Miramar map.”

The frequent patches have done a lot to improve performance of PUBG through these first four weeks. These noticeable gains have given some fans confidence that the developer will get close to a steady 30 frames per second across all Xbox One platforms.

Launching the Mirimar map will also help with that. Not only is it more content at no additional charge, but I’ve found during my PC play that the map is better optimized for higher and more consistent framerates.

The PC version of PUBG went into 1.0 on December 20. The studio has since shifted a lot of its attention toward Xbox One. Now, those coders and designers need to sit on their comfy chairs built out of $100 bills and finish that optimization process. If it does, it could grow that 3 million number to 6 million and beyond.