This book is one of a series that screams summer is here and vacation is coming. Our family has been having a great time with this, picking it up at in between moments, and challenging each other to find more than we have, once we finally admit to being stumped. So far, the youngest in our family is the best at this. Each picture tells you how many differences you should be able to spot in how much time. There are four different levels, and the expert and genius levels sure slow you down to notice minute detail. This quite satisfying frivolous pastime is just as good for a huge range of ages, and is so much better than similar books designed for children; while this one was designed to engage adults, there is no content inappropriate for kids, and kids love it too (especially when they get to share something with – or beat – grown-ups.) A book from this series would be great to throw in the car for a long road trip; it would be amusing on a tedious plane ride, or a delightful addition to that family reunion week at the beach. Besides being great for expanding mindful attention and developing observational skills, it’s just plain fun! We give it five stars.