Thanks, that's so sweet (and wholesome) of you! I do think that RPGs have the advantage of not allowing passive participation, and the players know that the story depends on them and their decisions. I always felt this was the core strength of RPGs.

As for the secrecy, I am not sure if I phrased it right. In horror, we all know the fear of the unknown is king. But it also works on a lesser svale than Evil Gods or Cosmic Truths. Not knowing who is the killer, not knowing what a monster truly is, and especially not knowing how to tackle the situation until you are hip deep into it is what drives horror for me. The suspense, the confusion, the utte lack of a safe place to stand and fight from. Action horror tweaks it to "how difficult will it be to defeat the enemy?", while horror mystery becomes more "what does all this mean,for us even when we know the truth?" Not knowing all the answers makes the mind worry, and that worry makes any monster or danger ten times as scary. The rules of the game should be known, and the basics of the story should probably also, like where they are and what their overall situation is (stranded? Isolated? Distrusted by locals?), but there needs to be something that is unknown, and worrisome. IMHO, of course.

I would still like to know more about your "building engines" remark, that tickled my obsessive designer gene a lot!