As I already explained, subject matter plays a part. My wife loves playing cards, so the keys you have to find (Which could constitute as a puzzle) appeal to her. The chess pieces appeal to me. While the water treatment puzzle is difficult, I'm not a sanitation engineer. I AM an avid chess player. See what I mean. It's little subtle things like that, that will make a game special for someone. So saying that it had "Better puzzles" like that's a fact, just isn't proper. That's all I'm sayin...Like I said. Are the ones in three more difficult. Hell yeah. And is that enjoyable. Definitely. But that doesn't always make something "better" since several people will interpret it differently.