your project is about a VGA signal or any video signal would do?

I have seen pong-like projects using PIC and x51 devices, so you could look at them to get some ideas how to generate a video signal that fits your project.

for PIC:

http://www.rickard.gunee.com/projects/...amesys.php
http://dt.prohosting.com/pic/pong.html

for ATmega:

http://jkdesign.de/avrprojec...20Page.htm

for x51:

http://www.ece.umr.edu/courses/c...fs99/gnop/

hth

orlando