The demoscene may be of interest if you're into optimising the binary for size and not the source:

http://www.hugi.scene.org/compo/

That one seems abandoned for a few years now but you can find plenty of tiny graphical effects here, executables are 512 bytes and below:

http://www.pouet.net/prodlist.php?type%5B%5D=32b&type%5B%5D=...