Pah. Rules is one thing. The important bit would be story. And as I found out, it is even questionable, how much of their rules they could copyright/make licenseable and furthermore, it is out for so long and with that ogl that it might even be considered public domain. But they seem to have paddled back exactly to that.
It was not a dumb move to have that ogl in the first place. The rules are rather badly designed. It might invoke nostalgia, but there are better rulesets out there, incorporating decades of experience. But they managed what early windows did. Flood the market.