Now that the developer of Flappy Birds yanked the game (I get the impression that happened to drum up even more attention for it) you need the next ridiculous game to play.
Enter Goat Simulator, where you try to avoid becoming roadkill. (If you fail, it's pretty graphic. Also, climbing any sort of ladders lets you see a bug in the software that makes the goat's head look like it's attached to the body with a rubber band.)
source : DC1.0.1