The goal of the game is to find all mines without looking at a field with a mine. You can open up a field by selecting look and the clicking on the field. If you look/open up a field with a mine you hit the mine ans lose the game. If there is not a mine, the number in the field shows by how many mines (0-8) the field is surrounded If you think that a field contains a mine mark it, to avoid an accidental opening You mark a field by selecting mark and then clicking on the field with the mine. A red flag is then shown. The clearing around feature is not look for mines or flags them for you. It is only speeding things up. when you have marked enough mines around a number (for examples 2 mines around a 2) then the other fields around the '2' are automatically opened, too. Of course, you hit a mine faster aswell, when you have marked an empty field
The idea for the clearing around feature, I have got from Kalejs Minesweeper Easy Game.A clone of the minesweeper game for the Nintendo 3DS browser you can play on froxot.de.