Good variety of puzzles designed to make you think - over 400 individual puzzles organized across 5 levels.All the puzzles will improve mental performance over time. If puzzlers start with the first, warm-up section, and work their way through the sections in order, by the time they get to section 5 they should notice a general improvement in mental performanceCasual puzzlers will be attracted by the four-colour design and the interesting mix of challenges