Well this prevents me from testing any games right off the bat. It would be a different story if I could choose which circles.
"Ordered list of your people in your circles Google gives the developer an ordered list of people from your circles. This tells the game developer the people you are most likely to want to engage with in the game. The order is based on your interactions across Google. This information could be used by the game to present you with people to play the game with, including to invite to the game, and to send gifts and messages."http://www.google.com/intl/en/+/learnmore/forum/