Zynga just revealed a teaser for its next big social game, an Indiana Jones-inspired creation called Adventure World.

The video trailer on the new Adventure World fan page says “you can explore exotic lands, solve ancient puzzles, and bring your friends along for a ride.” Zynga hasn’t described the game in more detail yet, but it appears to be a expansion into a new genre for the company, which is the leading maker of Facebook games.

The continuous roll-out of new games is important for Zynga, which has filed to go public in an initial public offering (IPO) at a potentially high valuation of $10 billion to $20 billion. Zynga, which has more than 275 million monthly active users, has been launching games more frequently this year. It released Empires & Allies in June, and that game now has 42 million monthly active users. By introducing fresh games on a regular cycle, Zynga can produce more consistent revenue growth over time and diversify its revenues beyond its top few games.

The New York Post reported yesterday that Zynga was planning to postpone its IPO, possibly from September to November, 2011. We suspect it’s true that Zynga will not go public at a time when the markets are volatile, as they’ve been in the past few weeks. Zynga filed to go public in June.