I made a pong clock based on the one here: http://123led.wordpress.com/about/
I then added a few more modes to it.
I took Nick’s clock as a base, tidied up a few bits of the code, added my own stuff for invaders, added some extra stuff to the fonts. It’s still not pretty code, but it works for now and when I get some more time I’ll be tidying it up a bit more and maybe add a couple more modes – maybe a binary clock mode and a pacman mode, and make the invaders more active.
The source code and required libraries can be downloaded here: http://pcbo.dcs.aber.ac.uk/downloads/PongClock2.40.tgz