If I may chip in not a game, but a management suggestion: You should write up a roadmap. No dates, no release shedule, just a list of things you are working on or planning to do, roughly ordered by how important or sure to be added they are.
In my experience, that's one of the most simple to add things there is, to reduce the influx of dupplicate ideas, and to asure people that there is more worthwhile stuff to come.