UWP exclusivity confirmed
http://www.windowscentral.com/game-mode-windows-10-will-power-xbox-one-project-scorpio
(not sure if it deserves own topic)
Previously, we were unable to ascertain whether *Game Mode would be a feature restricted to games built for the Universal Windows Platform (UWP)*, but it does appear that this could be the case. Our information states that games developed for the Windows 10, Xbox One, and Project Scorpio ecosystem *specifically need to be "Game Mode enabled" Universal Windows Apps (UWA)*.
http://www.windowscentral.com/game-mode-windows-10-will-power-xbox-one-project-scorpio
(not sure if it deserves own topic)