The promise of the $20 billion video game industry comes down to this: fat plumbers on jet packs, cartoon characters blown to bits, and a touchdown pass thrown against an opponent several time zones away. "The only way the companies can differentiate themselves is with better content," said Michael Pachter, an analyst at Wedbush Morgan Securities who follows the independent game publishers. At the video game industry's annual trade show, the Electronic Entertainment Expo, attention has focused on the battle between the major console makers -- Sony Corp, Nintendo Co., and Microsoft Corp. MSFT.O But the game publishers have been the biggest winners as the game box makers cut prices and spend millions to market the PlayStation 2, GameCube and Xbox, analysts have said.

Shares in the top U.S. game publishers are outperforming the Nasdaq by a wide margin again this year. First-quarter sales by the three that have reported -- Electronic Arts Inc., Activision Inc. and THQ Inc. -- were up a combined 45 percent. Looking to maintain that momentum, the game makers are showing off a mix of new games that aim to strike a balance between online offerings, which are seen as the wave of the future, and franchises built around familiar characters, which, like Hollywood sequels, are seen as a low risk proposition. I think you're going to see innovation in different genres people haven't tried before," Pachter said.