After hearing a lot about "Flappy Birds", how much of a rip off it was and how easy it was to create, I decided to have a go myself. This is my first go at any random world generation (Even if it is fairly simple at that) so be gentle! 

The game is pretty easy, you get score by going through the gaps between two sets of pipes, you die if you hit the pipe. I made this in GameMaker 8.1 so there isn't much to be impressed by, although the entire thing (Beyond sprite creation) was code which I wrote, I hope to write my own 2D game engine and remake this game in it soon (Although you might not see that).

I created this in such a way that everything is customizable by anyone, the height between the two pipes, time between another pipe generating, speed of the player and startup text can all be changed without having to do any extra work. Download game and source