I have read a few posts related to this topic and still unclear if my game I hope to make for this contest is acceptable. I wouldn't use any code, art, sounds, or music made before the contest started BUT I have done some planning on the game, put together a team, and it's based off an indie author's already published books but just the main characters and basic setting. I also put together a prototype of the basic features using the ultra simple game maker Construct 2 but wouldn't be using any art or code or even the same engine for my contest submission.
Basically, I have a team and a well thought out idea but no final assets or code that I would use in my submission. I don't want to rush to create this in a month only to be disqualified for a rule violation.