Like Sudoku, O'Ekaki provides an entertaining test of one's logic, using a grid of boxes as its playing field. But rather than leaving the player with nothing more than a bunch of numbers, O'Ekaki ends with a flourish: an interesting piece of art that evolves as boxes are darkened until the puzzle is successfully completed. It's a puzzle that utilizes both sides of a person's brain! And each puzzle's title is an amusing clue to the picture that will finally emerge.Simple instructions are included at the front of the book to get one started along with some useful tips. The puzzles challenge on several levels, from one pencil--beginner--to five pencils--expert--all resulting in a sometimes quite elaborate picture. Many of the O'Ekaki puzzles in O'Ekaki Heaven have a spiritual theme to their outcomes. Still, don't be fooled, some of the more difficult puzzles can be downright devilish!