I became interested in killer sudoku after I came across a handful of puzzles in Will Shortz's sudoku world championship book. I got bored of regular sudoku because it got kind of monotonous. Killer sudoku is a lot more fun and satisfying, and you really have to think to crack hard puzzles. Conversely, at least in my view, the key to solving regular sudoku is just staring at a puzzle until you find a hole.I was looking forward to getting this book after I finished all of the puzzles in Killer Sudoku: The Deadly New Dimension. Unfortunately, I found the puzzles in the book too easy. Even many of the puzzles in the "harder" sections -- Challening and Vexing, for example -- can be solved in under 10 minutes.In this book, the puzzles just aren't challenging. If you want to try to killer sudoku for the first time, I would recommend this book. If you want something a little tougher, get the Deadly New Dimension.