Epic Games said today that its Infinity Blade series of iOS games has sold more than $30 million to date. That suggests that console-quality games with outstanding 3D graphics have great potential on smartphones and tablets.

The sales include both the original Infinity Blade, launched in December 2010, and Infinity Blade II, released just a month ago for iOS. The game was developed by Epic’s Chair Entertainment division as a marquee title for the iPhone, iPad and iPod Touch platform.

Epic said the sequel is selling faster than the original. The first title took three months to hit $5 million in sales at a $5.99 download price (later discounted to $2.99). The second title hit $5 million in a month at a $6.99 price. That’s far short of major console game releases, but the numbers show that games released as exclusives for the iOS platform have become a big business.

Epic is also branching out with franchise extensions, including a digital novella, Infinity Blade: Awakening, from bestselling author Brandon Sanderson, Infinity Blade: Original Soundtrack, and Infinity Blade FX, a coin-operated version of the game in arcades.

“The success of the Infinity Blade franchise is testament to our talented team who is devoted to making games we want to play, all while using Unreal Engine technology to redefine what is expected from games on iOS devices,” said Michael Capps, Epic Games president. “We have so much more in store for players, and will continue to make great content for Apple’s evolving platforms.”