Learn the history and common features of puzzle games. Short paragraphs of easy-to-read text and plenty of colorful photos make reading simple and exciting. The book also includes a table of contents, fun facts, sidebars, comprehension questions, a glossary, an index, and a list of resources for further reading. Apex books have low reading levels (grades 2-3) but are designed for older students, with interest levels of grades 3-7.