I have to say this right here and right now: The rating system for puzzles could be improved. There are only four ratings to get (that I know of):
Borderline, Passable, Excellent, and Top Agent.
(lowest to highest)
But the problem is, is that on any puzzle (no matter how difficult or easy), getting it wrong twice gets you to Borderline. So, if you get a puzzle wrong twice, then you can pretty much go and guess all you want (which I sometimes did) because you know you can't get better. I think that after 3 wrong answers you should get Borderline, and then 2 wrong is either Passable or something in between B and P.