San Francisco-based Zynga announced its first licensed partnership this week, and it’s with Slingo, maker of one of the classic games that emerged in the early days of the web.

Zynga Slingo is essentially a remake of the popular game Slingo, with a few new twists. Slingo, meanwhile, can be thought of as a combination of slots and Bingo.

“What we have done is we have Zyngafied it,” says product manager Rich Sawel. “And we’ve brought it to the social space.”

As most people probably know, Zynga, which is now a publicly traded company, grew into the leading social gaming company by building its games on top of Facebook, which itself currently is poised to, later this year, become the hottest new publicly traded company since Google.

Zynga now has developed its own platform, independent of Facebook, but the bulk of its gaming audience still accesses the games via the big social network.

Slingo emerged long before the rise of social media and was one of the first online games to emerge back in 1995. Eric Lamendola, General Manager of Slingo Inc., told me last week that 55 million people have played the game since then.

Slingo features several popular characters – The Slingo Joker, Super Joker, Cherub and Devil.

The new “Zyngafied” has introduced some new features involving these characters, including “The Friend Joker,” whereby you can make The Joker become one of your Facebook friends; and an interaction with the Devil, which offers you a coin toss to (tails) lose all your points or (heads, which is the Slingo Cherub) and see your score skyrocket.

There are also a number of other featured improvements on the original game.

As with other Zynga games I’ve written about, this one pays careful attention to the sound effects, with the bells ringing and coins dropping familiar to anyone who’s visited a casino.

Whenever companies like Zynga release a new product, they have to strike the right balance of providing enough upside difficulty so that leading gamers will work to improve steadily, but enough simplicity that beginners don’t get frustrated and leave before improving.

At launch, Zynga Slingo is layered with five worlds that have nine stages each through which gamers can progress, with a speed bar that allows skilled players to rack up more points faster.

As the early wave of serious players proceed through this maze, the company analyzes their usage plus direct user feedback, and focuses on developing the next layers of the game going forward.

The trick remains staying far enough out ahead of the power gamers to keep them engaged. It’s like a dance, or maybe the best metaphor is evolution – the game has to evolve along with the player base.

Zynga’s Sawel is optimistic about the new game’s prospects. “We really love the ‘click-Zen’ of this particular game. It’s relaxing, especially after a long day at work.”