I'm still deciding on this one ... Might actually give it a go this year, depending on scheduling stuff. I am not personally a huge fan of the mythology surrounding the DK effect, nor do I get much of a charge out of most stories that place a hapless intellectual "ugly duckling" in a sea of foolish intellectual "swans," but therein might lie the potential for an interesting challenge...maybe. If my OCD driven pedantry can get past the initial hurdle. That, I suppose, is my own albatross to bear.
I do have one question / clarification request.
When you specify that [the fact that the MC is "smart"] "can't be revealed until the end," do you mean to the audience / player of the game, or the protagonist? I am assuming it's the latter, because the former option feels like it'd be close to impossible to execute without obfuscating the theme itself (i.e. if the unwitting player can't tell that the MC is the most competent person in the game, either througout the entire game or until the end, then how could the judges possibly know for sure if the game is even adhering to the constraint and isn't about a character who is actually the least competent person in a milleu of incompetents), but making sure, just in case,