I don't know how extensive you want the ad to be but I can think of a whooole list of more things to put under "who like", if you're interested. (Of course, I don't want to run you into the ground financially, but...)
You could add:
sierra, sierra games, sierra online, roberta williams, ken williams, ken and roberta williams, roberta and ken williams, quest games, old games, old school games, classic games, fantasy, high fantasy, epic fantasy, fairy tales, fairies, folklore, myths, mythology, adventures, sierra entertainment, vivendi, vivendi universal, phoenix online studios, the Silver Lining
You could also include each individual king's quest game (for instance: king's quest 1, kq1, and quest for the crown, maybe even king's quest 1 quest for the crown)
And again, remember to look for typos and add those in too.

Remember, you can never have too many tags on your ad!

Also, if you have it pay by clicks it will be cheaper for you, if that's a concern. It doesn't effect how many people it will show up on the page for.
Just some completely unwarranted advice.

I'm shutting up now.
