"We've found in certain instances that if we can partner with a [third-party] team when they want to do something special, then we can work with them on their game to help it reach that level that they want to see," he said.
"This was really nice for us. If you look a Tomb Raider and what it is as a game, it fits extremely well for our line-up next year alongside Quantum Break and Halo 5. We haven't announced everything that's coming next, but if you think about the game that Tomb Raider is, it fits really well for us. So the partnership I think is really a win-win."
Spencer went on to stress that while third-party exclusives are something that the Xbox division can do, he doesn't know if Xbox owners will see "a ton" of them going forward.