He submitted a Space Invaders clone inspired by the Atari 2600 game Megamania and the goal is to catch all classic computers with your laser before they hit you! The game runs on an MSX1 computer with at least a diskdrive. It also nicely demonstrates the extras you gain by using a media file in the challenge.
You still have until December 17th to submit your own entry and have a go at the prizes and eternal fame. So what's keeping you?
Relevant link: Retromania