Temple Run is a very simple game that relies on timing, but it is quite addictive.
The premise is simple: you're an Indiana Jones (tm) type character who just got out of a temple (after getting some goodies) and being chased by... well, doesn't matter! The idea is keep running!
So you basically have a couple commands: swipe up to jump, swipe down to duck, swipe left to turn / go left, and swipe right to turn / go right. Hit the commands at the right time and you'll keep running. Hit it wrong and you are caught!
It really is that simple.
There's bonus goodies, like special coins (which unlocks more characters), global leaderboards, and more.
Worth a try at least!