I've heard that there's a secret "easter egg" achievement in the new Google Play Games app, how can I get that achievement?
From the main listing of games in the Google Play Games app, you need to swipe the old Konami Code:
↑ Up, ↑ Up, ↓ Down, ↓ Down, ← Left, → Right, ← Left, → Right (and then when the retro button grid pops up), B, A, ▶ Start.
You should then see an achievement notification pop up.
via Android Central