Google has released a new version 3.1.36 of Google Play services and it is very slowly rolling out to devices now. Currently, most of the device sport Google Play services 3.0.27, and it expected the version 3.1.36 will bring massive updates. The most important of these would be changes that will push Google Play Games.
According to Android Police the new Google Play services update is getting the devices ready for Google Play Games. The new features include support for system wide notifications, standardized notifications managed by Google+, and cloud synced game saves to work across multiple devices. Google also includes parts of any modern gaming service, like matchmaking, leaderboard, achievements, lobbies and more. Google may show all these services at the Google I/O next week.