Both Call of Duty: Infinite Warfare and Call of Duty: Modern Warfare Remastered have been confirmed for a Windows Store release. Now the news-alert. As it turns out if you purchase through the Windows Store, you cannot play against (or with) players that have purchased it through say steam.
A source familiar to the matter recently informed windowscentral that the decision to segregate Windows 10 Store and Win32 PC platform players is entirely on Activision. There is nothing about the UWP toolset that prevents cross-play functionality, as seen with CD Projekt RED's upcoming GWENT card game.
These will be entirely separate products from the Xbox One versions of the game and won't take advantage of the Xbox Play Anywhere initiative. This eliminates both cross-platform multiplayer and purchases between Windows 10 and Xbox One, requiring two separate purchases to play on both platforms reports windowscentral. Activision just published a FAQ about it and here's the fine line on that:
Can I play Call of Duty: Infinite Warfare or Call of Duty: Modern Warfare Remastered for Windows 10 on Windows Store with my friends that are playing on Xbox One?
No, you can only play these titles with other users of Windows 10 on Windows Store.
Can I play Call of Duty: Infinite Warfare or Call of Duty: Modern Warfare Remastered for Windows 10 on Windows Store with my friends that are playing on another PC platform?
No, you can only play these titles with other users of Windows 10 on Windows Store.
While I can agree that Xbox One players and PC players should be segmented with everything speed and controllers/mouse players involved it is a little weird that Windows 10 Store players will be cut-off from other PC versions of the game.
Oh well, ... does anyone here actually buy at the Microsoft Store ?
Call of Duty Infinite Warfare on Windows Store cannot play with other platforms
