The head of games at Microsoft Phil Spencer has said that despite its desire to break down platform walls, the "vast majority" of its games are going to be on its own platforms.

Speaking to Kotaku, the exec was asked where it would draw the line on bringing its titles to other platforms. Spencer replied, saying that business is mostly going to be on Windows PC, Xbox and the forthcoming xCloud streaming service.

"The vast majority of what we do is going to be on Windows, it’s going to be on Xbox and it’s going to be on xCloud," Spencer said.

"And the nice thing about xCloud is that it is an Xbox in the cloud and so we don’t actually have to go build another version of the game. That is a distinct focus for [Xbox games chief] Matt Booty and the team. We value the relationships we have with the other companies that are out there. We think that we learn from them, we think we can help gaming grow all up with cross-play, cross-buy, cross-progression, all these things that we focus on. We think we’d be incredibly limited in pushing that vision if we weren’t strong on console and growingly strong on PC."

Spencer also discussed the company's service business in the wake of the memorandum of understanding signed by Microsoft's Azure cloud platform and Sony, saying that its services are used by games companies from around the industry.

"I think when you’re another gaming company and you’re looking for who you’re going to partner with, you could either go and invest tens of billions of dollars in trying to catch up, or you can figure out who your partners are," he said.

"And the nice thing for us is—you can focus on Sony, you can focus on a lot of companies—we have this thing called Microsoft Game Stack. We announced it at GDC: it’s DirectX, it’s Windows Studio, it’s Azure. Even [Google’s Phil] Harrison when he was on stage announcing Stadia was showing Havok, was showing Digital Studio, was showing things that we build—we’re going to have platform components, as Microsoft and as our gaming org that competitors use. We do think about the strength that we get as our platform grows and having great partnerships with gaming companies helping us grow that platform strength is important to us."