The formula may sound simple; the games are anything but. NaturalMotion puts an emphasis on stunning graphical detail in its games--the kind of rich visuals that you wouldn't imagine a handheld device could pull off. The characters move freely and smoothly in the games, which lean heavily on the built-in accelerometer found in iOS devices for their controls. Look no further than two recent NaturalMotion releases-- and --to see those attributes on full display.

Backbreaker 2: Vengeance HD is the iPad-only version to last year's for the iPhone and iPod touch, which itself was a sequel to the well-regarded . As with the iPhone version of Backbreaker 2, the new iPad-optimized release puts you in the cleats of a running back trying to run the length of a football field while avoiding opposing tacklers coming at you with very bad intentions. On-screen controls let you spin and deke just as you could in the original Backbreaker; you also gain the ability to jump over tacklers or "truck" (duck under) obstacles, be they low-hanging bars or flying bodies. The accelerometer-based controls allow you to tilt your iPad to change directions. Backbreaker 2 also ratchets up the game's Showboating feature--you rack up points for prancing into the endzone in a most unsporting manner--with a Super Showboat button that allows for even more high-scoring obnoxiousness.

Backbreaker 2 added a new Tackle Alley mode to the iPhone version, which also appears in this iPad release. In this mode, you're the hunter, not the hunted--you've got to chase down a ball-carrier, using those dekes, spins, and jumps to avoid any blockers who aim to stop you from reaching your intended destination.

Owners of the original iPad will certainly appreciate having an optimized version of Backbreaker 2 for their device. But iPad 2 owners are in for a real treat. NaturalMotion designed the game to take advantage of the newer tablet's processing power. That description, however, doesn't do justice to the look of Backbreaker 2: Vengeance HD--it's an amazingly intricate design. The football players cast realistic-looking shadows on the turf. When you're facing certain angles, you see the glare of the sun. In one particular stadium, as you run, you'll catch sight of a stadium jumbotron--which is showing a second rendered view of your run . When I met with NaturalMotion CEO Torsten Reil at last month's Worldwide Developer Conference, he described these graphical touches as the sort of thing you'd expect from a console game. Believe me, that's not just marketing talk.

I've been a big fan of the Backbreaker series since the original. I love the over-the-shoulder view the game provides and the heart-pounding thrill when an enemy tackler suddenly lurches into your field of vision. The Tackle Alley mode in Backbreaker 2 extends the fun even further. I've also been critical of some of the on-screen controls for the Backbreaker games--it's too easy to tap the wrong button--and that's a problem that persists with this iPad version. I've often tried to jump over an obstacle by tapping the screen, but sometimes my tap will occur too close to the Accelerate button, and I'll just wind up sprinting into the obstacle. Given the iPad's ample screen space, I don't think there's a reason for the buttons to be placed that close together.