To me a boardgame should mostly be fun to play. It may never feel like work (well maybe the setting up). Keep it simple and intuitive. Make sure the rules match the theme so the game works intuitive.
This summer I will spend as much time as possible on a wargame that has some features that me and my friends enjoy alot! Will be a challenge to fix some problems and try to come up with stuff that adds to the game even more.