Quote Originally Posted by Avatar View Post
I did not know that. How do they work, then?
They use .appx files, which is a proprietary new format created by Microsoft to unify app distribution between desktop, tablet and phone environments. Think of it as an .apk in Android terms.

This is part of the new Universal Windows Platform (UWP) push by Microsoft and, sadly, side-loading .appx files is prohibited in Windows 8/10. So I believe your only source for these new games will be the Windows Store.