In short, it's disturbing, and I wouldn't wish the addiction on my very worst enemy (watch your back, Hedaya!). OK, now that you've been sufficiently warned, I feel like I can proceed with a clean conscience.
Here's the pitch: It's like the Pacifism mode in Geometry Wars 2, having a small ship luring hordes of enemies into traps, except those boring exploding gates have been replaced with tons of different power ups that let your valiant arrow fight back against the ever-encroaching waves of enemy dots with destructive shock waves, dot-sucking vortexes and personal force fields.
Killing several dots in quick succession boots your score which, at game's end, you can compare to all your other friends who are similarly afflicted.
And that's it.
The premise is simplicity itself, but the real strength of TTL isn't necessarily in the mechanics but in how flawlessly they mesh with the game's platform and aesthetics.
A tilt-only game is obviously perfect for the iPhone, but ingeniously, you never have to tilt so far that you have anything less than an optimal viewing angle. That's exactly want you'll want too, if only to enjoy the colorful mod-inspired graphics (to say nothing of the zippy theme music, which sounds like it could have been lifted right from an Austin Powers chase scene).
There's also a thread of good-natured humor buoying the whole project. For example: Players receive an award called "Highest Combo Imaginable" upon their first 5x combo, shortly before getting an award called "We Lied" upon hitting 20x. It's subtle, but the occasional chuckle helps to cushion the blow when a wrong turn infuriatingly sends your record-breaking score into the toilet.
... Three times, by the way. Three. That's the number of times while writing this brief piece that I've been so overwhelmed by thinking about Tilt to Live that I had to play a quick game of Tilt to Live. If there's a more rousing or honest endorsement I can give to the thing, I honestly don't know what it is.
Tilt to Live (One Man Left, $1.99):