I recently did some playing around with one of game of Granular called Kbounce. I have played many games, but I find KBounce among one of the best games I have ever played. It is very simple to play.This game is available under amusement section of the KMenu in Granular. At the game window, you have to press ctrl+N to start the game. Then you have to complete the 75% of area by creating the walls. When the area covered is 75% or more, next stage will come with one more ball.
Over all the game is good and i think you will learn more after playing it.Have fun.