If for whatever reason you haven't played Ratchet & Clank: A Crack in Time, there are only two acceptable reasons - you're broke or you don't have a PlayStation 3. "I'm not interested" is not acceptable; the game is good, I say.
But there really are no reasons you shouldn't check on the Clank "Race Through Time" mini-game that Isnomniac has up online. It's a timed side-scrolling affair that has Clank racing through obstacles to a finish line, with the ability to slow down and speed up time. The game is played with the keyboard, and I'll admit I'm terrible at it. The game features Facebook Connect support which I opted not to do, since putting up my miserable times online would reveal to the world how bad at videogames I am.
However, if you think you can do better than I did, give it a go. Do well enough, and you can unlock some neat Ratchet & Clank wallpapers for your troubles. Good luck with that!