Hop, shoot, duck - and pray. The odds facing faith-based video game developers are nothing short of overwhelming as they try to enter the mainstream marketplace.

With a focus on eliminating violent content, religious game makers' digital heroes strike with the power of God and heal with Scripture reading.

Developers are banking on the success of religious entertainment, the "Left Behind" books and Mel Gibson's "The Passion of the Christ," to open retailers' eyes.

"Rather than fight it, religious folks are now trying to offer alternative venues for both content and technology," said David Batstone, a theology and ethics professor at the University of San Francisco.

The early results are mixed in a market of about 40 faith-based titles. The PC game "Catechumen," one of the best-selling Christian titles, has moved 70,000 copies at $19.95.

By comparison, a blockbuster like "Half-Life," a violent first-person shooter game, has sold 3 or 4 million copies in a $6.9 billion industry

, said William Harms, senior editor for "PC Gamer," a magazine that reports on and reviews games.