Of course, the game is currently very abstract and undefined. However, as this community seems to be a bit about defining it, I'd like to talk a bit about what the theme and the story of the game are going to be! The story concept kind of dictates the gameplay, too (or the other way around, I suppose: a story could also be written to fit a gameplay concept), so there probably isn't much point to keeping them separate - at least initially.
So how about it? What will / can the theme be? The concept? It's going to be interesting to see where this goes!