Perhaps there should be specific requirements/guidelines for the maps; otherwise 'open-ended' is too broad to use for comparisons between submitted maps.
Having a guideline would help a guy like me from making too crazy a map... as it is, I think I'm going to scrap 'A Dark Place' and start over, with similar concepts, but more open, maybe even try a skybox. It's frustrating putting a lot of time into a map, that's ends up not being very useful... but hey, lot's of practice!