Thanks for the reply @goose20. It is really nice to have the interaction and feedback.
I was just reading the Dtube curation reward comments and see that Dtube is attempting to increase its curation of Dtube authors by returning some rewards to curators. Keeping within this vein, I would say that encouraging participation should be a major focus, so keeping the contest requirements low might be a good idea. Perhaps simply ask that contestants post a screen capture of one of their SoG games and talk about why they took that particular shot?