If you know anything at all about Google, it should be that the company is filled with 100% unapologetic geeks. And as such, they love to put Easter eggs into products, especially one specific Easter egg, which has been in a few different products, and has now been found in the new Google Play Games app...
Source: http://www.phonearena.com/news/We-should-have-known-the-Google-Play-Games-app-would-have-this-Easter-Egg_id45735
Source: http://www.phonearena.com/news/We-should-have-known-the-Google-Play-Games-app-would-have-this-Easter-Egg_id45735