Zynga, maker of popular Facebook games like Farmville and Mafia Wars, has announced today that CityVille will be its first social building game on Google Plus. Zynga Poker launched with the rest of the Google Plus game platform in August, but this is Zynga’s first Google game in the mold of their virally successful Facebook titles.

Zynga has over 146 million users of its social games, but they’re almost entirely on Facebook. But as we reported in July 2010, Google quietly invested over $100 million in the gaming company, ensuring that major Zynga titles on the Google platform were only a matter of time.

Zynga is Building its Empire
CityVille – like FarmVille meets Sim City – already boasts over 72 million players on Facebook (and that’s down from a peak of over 100 million), which is 30 million more people than there are on Google Plus altogether, according to the latest estimates. Suffice it to say, it will be a long time before Google Plus can provide users at Facebook’s scale.
But Facebook could use the competition, and game producers like Zynga are all too happy to help create it. Zynga has expressed dissatisfaction with the terms of its relationship with Facebook for a long time, and it has channeled its rapid growth into more than one partnership outside Facebook, including Yahoo, MSN Game Portal, and of course Google.
The Potential of Google Games
Google, for its part, has been building features for a game platform for a year or longer, and analysts believe that Google Plus games represent an enormous opportunity for the company and game developers alike. As Tricia Duryee at AllThingsD reported in July, Google may spur that opportunity along by undercutting Facebook on in-app fees and other costs for developers.
Google Plus already has some titles that compete with Zynga’s big genres, including a mythical city-building game called City of Wonder and an organized crime game called Crime City, but Zynga is the big name in social gaming, and today’s announcement brings the game style that made it successful to Google Plus.
Have you played any Google Plus games? Tell us which ones in the comments.