Simple Raspberry pi game

We are testing a touch screen on our raspberry pi, and would like a very simple game to test the touch screen. the touch is just a mouse click emulator, so there's no fancy code for the touch screen. Something like raining bubbles and each time a bubble is touched, it bursts/explodes. this will allow us to demonstrate the touch screen. The screen will be in portrait mode, not landscape so the game will need to be portrait mode. we'd like to be be able to change the items falling by changing the png's and being able to change the background would also be helpful. simple score counter. no need for entering names, as this is just a tool. this is not a high value project as it's just a test for our touch screen, so no silly quotes please. stay inside the cost guidelines.