So yes, I've been rather addicted to this simple run-and-avoid-obstacles game. From the graphics on the title screen I gather you're making off with some idol from some cursed ruins and then a couple of devil monkeys start chasing after you. There's really no other lore to go on, and when you start unlocking different characters later on like a geisha and football player, all logic goes out the window. But that doesn't really matter because you're in a desperate struggle for points.
The points are all that matter, and yet they don't matter at all. The chase for the high score is somewhat maddening, considering we live in an era where high score lists are all but extinct. But even if you don't nail a new personal best, Temple Run has a shop where you can spend the coins you collect on enhancing powers up and buying new characters. There's always something better to buy and rank up... until there isn't. And then you write a review.
I won't go into excessive detail because the game doesn't either. The jump, duck, and slide out of the way of trees and pits while outrunning some monkeys. Hit something and you die, Game Over. A score is calculated from how far you ran plus how many coins you collected, and then factored with a multiplier that increases every time you complete one of the game's general objectives (yes, Temple Run has achievements too).
If you hit a new high score, you play again. If you don't hit a new high score, you play again. That's about it. The worst part is, half of the deaths usually aren't even your fault. The game is quite glitchy, at least on Android, and you'll frequently clip through ledges, slide instead of jump, or my personal favorite: the super-speed power-up runs you off the edge instead of auto-turning. It seems like that last one is finally fixed after a recent update, but man, is it counter-intuitive to not grab a power-up because it has the chance to kill you. (also, poisonous mushroom in Super Mario Bros.: The Lost Levels are dumb.)
Overall, I spent far too much time on a game that is about as straightforward as they come. Temple Run isn't bad, it isn't great, but it is fun. And is there anything else we expect out of a mobile distraction?