I don't like to comment until I've completed a game. With this one I've gotten to the closing credits in two separate places and still haven't finished. But I wanted to send my congrats to the gang that built this terrific puzzle game. Great game, great teamwork. A true All Star lineup of puzzle constructors. (Constrictors?) Besides that whopper S.5 at the end, which I'm still trying to grok, I got stuck on S.4 for three weeks. I'd gone through the rest of the game in 11 days. Also, a couple of times the game seemed to change from under me while I was playing. Specifically, the B.18 puzzle and AB.5. Was that my imagination? Anyway, many thanks again to all.