Zynga Game Network, a San Francisco-based gaming company, on Wednesday raised $29 million in a new round led by behemoth VC firm Kleiner Perkins Caufield & Byers.

Institutional Venture Partners and return backers Avalon Ventures, Foundry Group, and Union Square Ventures joined in the series B funding of the social gaming company that previously raised $15 million.

“We have a really high bar when it comes to investments,” said a statement from  partner John Doerr of KPCB, which has a knack for investing in such successful companies as Amazon.com, America Online, Genentech, Google, Netscape, and Sun Microsystems.

The investment by the leading VC firm in the startup, which makes free poker, puzzle, and other games for social-networking web sites, is a sign of investors’growing interest in services shared on social networks.

“Social gaming is one of the most exciting applications of the consumer Internet,” Mr. Doerr said in the statement. “Zynga gives its millions of customers a new way to make friends and have fun on the Web.”

The social gaming company, which was founded a year ago by Mark Pincus, 42, who previously co-founded social networking site Tribe and enterprise software company SupportSoft, delivers casino games, word games, board games, role playing games, and party games to various social-networking web sites such as Facebook, Bebo, Friendster, and meebo.

The company also announced Wednesday that Kleiner Perkins partner and former co-founder and chief creative officer of Electronic Arts, Bing Gordon, will take a director role in building the company. He will join LinkedIn’s chairman, Reid Hoffman, Foundry Group's Brad Feld, and Zynga CEO Mark Pincus on the company’s board of directors.

In addition, Zynga, which claims 55 million registered players, announced Wednesday that is has acquired YoVille, the largest virtual world game on Facebook.

Zynga might use some of the new funding money to acquire more competitors and assert its position as the No. 1  social-gaming company on the web.