Oh Arduino, is there anything you can't do? There's plenty to love about Eiji Hayashi's home-made Laser Command game: its palm-sized cube form-factor for a start, the simple 8x8 LED matrix display and its minimal controls, but it's the fact that you play the game by shining a laser pointer at the screen that really impresses. Input takes advantage of the fact that the LED matrix can not only output light when current is applied, but output current when light - such as from the laser pointer - is applied.
Video demo after the cut
In fact, the matrix rapidly flips between input and output modes, so fast that you can't spot the blinking. In output mode, you see an array of falling pixels that you have to zap with the laser pointer; in input mode, the matrix tracks where the pointer's beam is falling.
Even better, Hayashi has made all the code and schematics available on his site so if you know which end of a soldering iron is which, you should be able to put this together yourself. If you do, please make us one too!
[via Hack a Day]