I have some idea and it's not really complicated, my idea is called a strategy fleet formation and lost in deep story telling.
About a strategy fleet formation, a contestant could submit plans for fleet formations optimized for different battle scenarios, like ambushes or large scale invasions.
The second idea is lost in deep story telling, a participant have submit short narratives about a pilot lost in deep space, encontering unknown threats or making impossible decisions.
About a reward you can have 7$ or 5$, not that big, because it's really not a big contest how ever it's just about a having fun and we can share our story in this contest :D, I hope to enjoy ;p