Doesn't do any cloud save at all. The option for that disappeared from account sync options (was visible once but suddenly disappeared). Automatic sign-in from game apparently worked, when I open a game it shows the Play Games icon and my username. This option is also not visible in the settings of Play Games itself. No solution for these issues can be found on Google help pages. I installed my games on my new phone, and none of my scores are carried over. Totally useless app!