For the past few evenings Ive been looking into this. So far, its going quite well
I have completed the following:
Join a quick game. Currently this is fixed to 2 players. It should be able to support 8 players.
Send unreliable messages between the 2 android devices. Some of these messages are...
Im releasing v1.0.1 of my Module for Google Game Services.
==EDIT== V2 has been released https://www.cerberus-x.com/community/threads/google-play-game-services-v1-0-1.475/post-8530
If you are interested on how I built it, I've written up a blog post here
Module can be downloaded from here...