Sunset Overdrive ultimately became an exclusive title for the Xbox One because Microsoft allowed developer Insomniac Games to retain the rights to the game.
In an interview with IGN, co-creator Marcus Smith said the following:
“We pitched it a few different places, and it was really important to [Insomniac CEO] Ted [Price] that we own the IP, so some of the conversations broke down over that. With Microsoft, they just came in very energetic and excited to work with Insomniac, period.”
Of course, Insomniac Games we previously a company that developed exclusively for Sony, creating iconic series like Spyro the Dragon and Ratchet & Clank.