I like a big onion..
easy simple game at the core - where all players can have fun w/o needing anything from anyone - easy, fun, shoot-um-up.
then a layer for missions: missions, counter missions, etc - to add something for those looking for that kind of thing.
then a layer for the C&C : to give the generals / XOs / RTOs something to do besides passing out missions.
then a layer for the role players : to add something for those looking for that kind of thing.
Wrap the whole thing in a theme and serve with good friends, good weather, good food, good paint, and plenty of Pabst Blue Ribbon.
--- ¡¡¡pıɐ-ןooʞ ǝɥʇ ʞuıɹp ʇ,uop---