Even in the Web 2.0 universe, a literally two-dimensional concept can give way to a cult classic, provided it contains a compelling kernel of originality and ways to brand the finished product as your own. The sledding game "Line Rider" humbly began as an online Flash game in which a boy sledded down a track of your design, but it quickly garnered fans who created fantastically creative tracks across which the rider dramatically tumbles and swoops.
It's only fitting that "Line Rider" make the leap onto the iPhone. "Line Rider iRide" ($2.99) lets your fingers draw the track, pinching and pulling the iPhone screen to zoom in and out for a closer look. The basic controls to draw freehand, lay down a straight line, and erase lines are there. So are buttons to undo lines, move around the screen, leave a placeholder, and flag the rider's current position. If you have a LineRider.com account, you can make a name for yourself by sharing your sledding course, or download someone else's track to admire.
Although you can give your courses limitless scenery and outlandish jumps, the ride itself will be staunchly guided by Newtonian physics. Make your pawn fly too high, fall too far, or loop at unnatural angles, and he'll skid, thud, or somersault to his demise. Keeping him going right-side up is addictive--and harder than you might imagine. Just consider that the next time you hurtle down those snow-covered slopes.