This was a gift for our 7yo for Christmas, who is a math whiz and logic nut.  It was the perfect gift.  It engages his little brain in a different logic puzzle every time we play.  If you play to 30, like the instructions say (a codemaker gets 1 point for every guess the codebreaker takes), he beats me every time. He is better at logic! He always solves in fewer guesses than I do.