Hi there! If you wrote a significant chunk of polished code prior to the jam's start date, it would be good to try working with something new. Something that amounts to brainstorming or starting to sketch out an idea is fine, though. If you publish your game after the jam ends, it won't count as an entry. But if you run into trouble close to the end date, you can always check in with me; I'm totally willing to accept late submissions in cases of technical difficulties, unexpected setbacks, etc.
Thanks for joining! I hope you have a great first jam experience!