The board is divided into cells, with mines randomly distributed. To win, you need to open all the cells. The number on a cell shows the number of mines adjacent to it. Using this information, you can determine cells that are safe, and cells that contain mines. Cells suspected of being mines can be marked with a flag check the 'Place a flag'.
To start a new game, you can click on the Reset button at the top of the board. The remaining number of mines is displayed in the left corner, and the game timer is displayed in the right corner.