When you buy this book you get an electronic version (PDF file) of the interior of this book. Slitherlink is a fun and addicting logic puzzle game. The goal seems to be very simple, connect the dots. However, do not be fooled by its simplicity, Slitherlink is a very challenging logic puzzle and is an excellent brain game. This book is ideal for you if you love to solve difficult big Slitherlink puzzles. You do not need to wade through tons of easy Slitherlink puzzles before getting to the real brain teasers. You will experience Slitherlink 20x20, Slitherlink 23x23 and Slitherlink 25x25. You get the perfect mix of different sizes of Slitherlink puzzles to keep you entertained for weeks. Once you pick up this book, you won't be able to put it back down. You have been warned! Slitherlink Mixed Grids - Hard is a collection of 276 puzzles: 72 hard Slitherlink 20x20 puzzles 72 hard Slitherlink 23x23 puzzles 72 hard Slitherlink 25x25 puzzles 60 extra logic puzzles I guarantee that every logic puzzle in this Slitherlink puzzle book has been carefully checked to ensure that each puzzle has only 1 solution. None of the puzzles in this book will appear in any of the other PuzzleBooks.net books. Slitherlink is also known as Fences, Loop the Loop, Dotty Dilemma, Sli-Lin, Great Wall of China, Takegaki, Loopy, Ouroboros, Suriza and Slither Link.