I was really excited about Google Game Services and I've even implemented them into my game, but then I discovered users need a Google+ account (not just a Google account) in order to use high-scores/achievements.
Now I'm considering whether or not to actually publish the version of the game with achievements/high-scores...
aren't games on google+ now being deprecated?
anyway, I think one logic game there had an internal scoreboard (as it was being published from many other locations) and scoreboard copy was also being pushed to g+.
Yes, google+ games are being deprecated. But Google Game Services is something very different, it's an API that makes it easy for game developers to implement achievements, scoreboards and multiplayer. It turns out that your users need a google+ account to get access to these features, thus making them less awesome as I originally thought.
Now I'm considering whether or not to actually publish the version of the game with achievements/high-scores...