9 year old... what kind of game might you run for him?

So I'm thinking of getting my 9year old son to play SF in some kind of small scale adventure.<div><br /></div><div>He's been playing Hero Clix and AGTFOS with me lately so I was wondering if he is ready for an RPG.</div><div><br /></div><div>What sort of game ideas might you try with such a young person?  I don't know how his mother would feel if I let him kill bad guys... meh... </div>