With so many variations of the game, it does not get tired to surprise their fans. She has several other names, one of which is a magic square. It's true there is something mystical in this arrangement of numbers. This square is made up of 9 * 9 cells, but also it is divided in smaller squares whose sides are three cells. As a result, we obtain a 81 cell already in the field. Each has its own number should be. When you start the game Sudoku Challenge HTML5, you'll see in some of the cells of the numbers that are called prompts. This game has its own meaning, which is to fill all the cells with certain rules. The most important rule is: in every column, row, in a small small square each digit from 1 to 9 must meet only one time. The complexity of the game Ultimate Sudoku HTML5 will depend on the number of so-called clues early on. The more, the less you have to think about the location numbers. In this game there is only one solution, and in another way to solve it is impossible. Everything will depend only on your wits and powers of observation. The Ultimate Sudoku game has three difficulty levels. In the first almost a third of the cells already filled in, and you will pass this puzzle in a few minutes. But on the third level of complexity of the field will be almost pure, and can take almost an hour to fill all cells.