What is the Game, and What Makes a Good System?

In a confluence of events, I ran my first session of Mothership this week, after having played it most weeks for the last six months or so, coinciding with the Paul Beakley of Indie Game Reading Club posting his review of the game. I think it is a well articulated critique, echoing some points made in Dwiz' review over on Knight at the Opera (now sadly unavailable). However, as a self-professed "system-curious indie guy", I think Paul underestimates the value of a simple but effective chassis (or at least, he comes to the conclusion that it is not what he wants out of a game). The strength of the stress system is how simple it is to interact with - yes, the rules in the booklet may not be enough to fully drive play on their own, but perhaps that was never the intention? I would argue that the core rules of Mothership offer just half of the game, with the other half left open to be filled by modules or an enterprising game master: The quality of the rules should the...