Plus One is very interesting and addictive game. The rules are simple and easy to learn. When you click one of the tiles you add +1 to the numbers of the nearby tiles (up, down, left, right). The number of the clicked tile doesn't change! When you hold down a tile you can see how the nearby tiles will change. Your goal is to make the second board exactly like the first one. When you complete the level you can proceed to the next one. The game difficulty increases according to the level. You must try to reach as high level as possible. If you login you can compare your result with other players. Try to be the best! The game can became very difficult so be careful! It is a good start to try the tutorial section of the game. Enjoy!