In the Squares you make a move and then your computer opponent makes a move. The object is to put the forth side on the square and close the box. To win you must close more of the squares than your opponent. To do this you have to avoid putting the third side on a box because then it will be your opponents turn and they will get to put on the forth side and close the square. You can’t always avoid putting on the third side of the square but you have to try to do it less than your opponent.
When you complete a square it will turn purple and when your opponent completes a square it will turn orange. When you complete a square you have to make another move and continue until you cannot complete a square, then it is your opponent’s turn again.
Generally in the late stages of the game you can make a run of completing several squares. But when you finish your turn your opponent will probably make a run of several squares too. You should watch the areas and try to give your opponent as small an area as possible in which to make a run. So if you have to put on the third side of a square, try to pick a small contained area for your opponent to complete.
The game takes practice so that you can begin to see the patterns of how the runs are made. Just keep playing it and practicing. Good luck!