This is the good old Sodoku game we all love to be frustrated with. Let no matches exist in any direction from one individuial number, meaning that if a 1 exists vertically, horizontally, or diagnolly, you will find that the number is not correct- the most intricate puzzle game in common circulation in this era! However, this game- while Sodoku has the slight issue that you can't overwrite the numbers once you place them, like playing in pen- and furthermore you can't seem to restart without reloading- that being said.. take your time, even if you are rushing the clock, because you can't afford to hit the end and be stuck.. like me. Again, I've failed at Sodoku.. I should take my own advice.