It would be a little difficult to add a planet to this solar system, since I've already accounted for them all; in total, 9 planets, 2 of which are habitable (Most games take place on the 4th planet from the sun, while orcs and other such creatures come from the 3rd), with 2 gas giants and 2 ice giants. ^_^ It's a neat idea, but I don't think I'd be able to use it in this particular case.