What would be helpful is to have some debugging information on why GPGS isn’t working. “It’s broke. Fix it” isn’t very helpful, in particular with really big plugins like GPGS. What would be a lot more helpful is a sample project with your code in it (complete with build.settings and config.lua) and a capture of an “adb logcat” sessions looking for errors from Google about why it’s not working. It’s really hard to speculate as to why something isn’t working for you.
Rob