I love logic based games, and this is one of the most logic based games i have ever seen(except the political question and red-herring one, as you had to know some insight to actually deal with these question. Don't get me wrong, i know you can solve those without knowing those two things(which i did) but it was still annoying) AND i have to be honest, in the very last puzzle, i guessed the third answer(correctly on the first try hah!). But all those weird symbols just screwed with my head to think straight.
I can't agree with the previous poster at all though, every puzzle had only one real solution, a logical one.
One downside though, the navigating(clickin on screen) wasn't that good, especially considering you couldn't go back if you accidently clicked a message away.
P.s.: I never solved a puzzle with the hints...i looked at one hint just to see what it was about, it was far more confusing than just to deal with the question on your own, just with plain logic.