The problem with this, and it has been discussed before, is that those who
have extensive (internal, or even external but not well documented or
supported) libraries start off with a huge advantage over those who come
into it fresh. There are quite a few pretty extensive libraries that
are in
fact allowed, and you can use your own library as well if you document it,
release it well in advance of the contest, and get it approved. I've been
working on a massively multiplayer game for a year and a half. Now I'm
going to take that, put in some models that fit the theme, and call it a
day. Not so good...
The idea of the contest is sort of to put everyone on a level playing
field,
and allow freedom of experimentation. I don't know about some people, but
when I am limited on time I tend to come up with very unique code design
that I don't often use in my full projects, sometimes I even learn
something
from it besides just having a good time :)
A week really is enough time to accomplish some great things or at least a
great start to a new project. More time than that and it's too easy to put
things off or have feature creep really set in, less time is just too
rushed; although that's an experience in itself.