I have no problem with it being a rated entry if a significant or meaningful portion was done during the game jam. I would like everyone to be able to get rated, and enjoy the jam, but not at cost of the people who done 100% work during the jam.
So my approach would be: Do as much work as possible to deliver something meaningful beyond what you already have. Decide in your own conscience if you should take part in the rating. If so, clearly state what has been done during the jam, what outside of it, in the entry page. If not, just tell me, I will mark it in the jam, there should be an option to exclude somewhere.