As per the rules:
"You must make all assets and code yourself or by your team within the time frame of this jam. Any templates, plug-ins and/or pre-builds will not count in the originality department."
I do appreciate your honesty and it is a valid question to anyone else in a similar thinking space. As far as winning a prize, I would say no because it would violate the rules. But if you would like to finish it up and complete your first game, I would encourage you to do so. It will be a huge confidence booster for you. We will play it and you will get feedback and help... who knows? you might make a new friend or two here...
But to be clear and not have misunderstandings from anyone else, DO NOT START BEFORE THE JAM STARTS. Follow the rules if you want to win a prize, or have a spot on the honorable mentions section.
There will be a future jam to submit any old projects you have been working on