I realize that this is a little bit confusing. There is really no way to verify if it's a completely fresh game. I am allowing re-use of existing libraries/code because to start from 100% scratch is for many a too difficult task. To more understand what I mean I should explain the motivation behind creating this jam. I want to grow the community. I want more people to discover this niche genre that I myself love so much, and I want developers to create new dungeon crawlers that the world haven't seen before. If someone will submit their life's work, a dungeon crawler game they've worked on for years and years, for this jam then I will not disqualify that. I will not encourage that either, hence the rules. However, if one or more games are tied after the voting then the judges assessment will be the decider and whether this is a fresh project or not is something we'll be looking at.

I apologize for the lack of clarity on this and I hope my explanation helps a little bit :)

PS: You mention that a lot of people showed their work and that they are already decent games. I haven't seen much of that. Perhaps one or two that are a little bit beyond tech-demo state. Keep in mind that on that server there are many gamedevs that are working on dungeon crawlers outside of this jam. :)