Wow, you guys are leagues ahead of me. So far the only thing I completed (more or less) is create a base mod I can work with (selection of frame, screen background, walls, backdrops, PC portraits & icons, custom sounds). Seems like changing the medium didn't change the way I go about designing...
I've got no story yet and 0% done on the mod itself.
On the other hand, right now I'm actually getting paid for developping a story concept and writing something, so no wonder at the moment the contest smells like work for me, too.