To me the trick is preserve some kind of backward compatibility with chess while finding a way to increase the strategic content. Ironically stuff like increasing the board size like in 3D chess variants, can actually reduce the strategic content by reducing the role of long-term factors like pawn structure.
EDIT: I can see some combination of the game's features -- particularly the king "touchdown" -- sort of working against the strategic content. IE people just playing gimmick openings to sneak their king across.