Ok, here is the game Marshall 4 that you can play online (click the green flag to start). It's created entirely in Scratch, the kid-friendly programming language designed at MIT. In Scratch, code is made up of lego-like blocks that you snap together. I've made a few things in Scratch, and let me tell you, this game Marshall 4 must have been a bear to build, not because Scratch is hard (it isn't), but because it's really for making much simpler games, animations and objects. Not only is a fun to play platform game, the animation of the ball is sophisticated, there are no bugs (at least that i could find), and the game is enough of a challenge that I wanted to keep playing. That's rather impressive for a Scratch game, it has high ratings. After playing, take a look at the code to get a good human-readable understanding of how the game was made. Remember that in Scratch, each sprite (like the Marshall ball, or a key, or a button) has its own code that tells it what to do, so try looking at the code for each sprite, and you can even try to remix it and create your own fork of the game (as 217 others have done so far).-LT