It has since doubled down on the "ville" games, launching a slew that includes CastleVille, CityVille and Petville, and has unleashed what it calls "with friends" games, including Words with Friends and Hanging with Friends, which are akin to virtual knock-offs of traditional games like Scrabble and Hangman.

Yet, Zynga's shares have continued to fall since its public launch on the Nasdaq, which is a sign investors are disappointed with its portfolio and the handling of its operations in the first eight months of public trade. Zynga, after all, is tracking toward a decline in daily active users from this year's first quarter. 

However, Poker continues to be a bright spot for Zynga, which may be one reason the San Francisco-based game giant has recently revisited its roots by developing traditional casino games like Bingo and Slots.

The renewed focus on traditional casino games also comes amid sweeping changes to the online gambling industry.