Microsoft's recent push into Windows 10 gaming came too late to bring certain Xbox One exclusives to the platform, says Xbox head Phil Spencer.

The company showed off flashy demos of Crackdown 3, Scalebound, and Quantum Break at Gamescom 2015 last week, but no Windows support was announced.

Speaking to PC Gamer, Spencer explained the decision thus: "To be completely honest with you, we started those games before we really looked at expanding into Windows."

"Going to those teams mid-cycle and saying: ‘Hey, by the way, I want to add a platform,’ didn’t really feel like necessarily the best way to end up with the best result for the game."

Some Xbox games from the past, like the Gears of War remaster, are coming to Windows as well; Spencer suggested that others could return "purely on PC."

"I definitely want to build out our Windows games portfolio, and we’re making slow progress on that," said Spencer, "but slow in a way that I think is good, because we’re being deliberate about the games that we’re deciding and make sure we have a real plan."

Parts of that plan include Fable Legends and Halo Wars 2, both slated for PC releases alongside Xbox One.