In this demo a little tank across the bottom of the screen and shoots bullets with the O button. It's a simple 2d drawing interface consisting of drawLineX, drawLineY, drawCircle, drawRect, fillRect. This is also a example of double buffering.
Tag. The title pretty much explains the game, both players play on one PSP, one player uses the buttons, the other uses the D-Pad. After you are tagged, you have 1 second to run before you can be tagged again.