On the heels of the Google+ announcement, Facebook a bigger gaming screen and noted that people who play games on the site will have a separate stream that will show their high scores, as well as friends' gaming activity.

All the analysts said Facebook will have to push itself to come up with ways to keep users engaged with the games on its site.

"The best response for Facebook in a situation like this would to substantially enhance its already mature gaming ecosystem and platform," said Brad Shimmin, an analyst with CurrentAnalysis. "They should take, for example, a popular game such as Angry Birds and socialize it."

Facebook also will have to keep game developers happy.

"What Facebook might do is promote their platform to developers as a vehicle that gives them the most visibility and the best chance for commercial success," said Olds. "Google does a pretty good job of wooing developers and will certainly put forward a compelling pitch to game creators. Facebook needs to make sure that they're offering at least as good a deal as Google, and make sure they emphasize their massive user base compared to Google+."