Minesweeper

Click a cell to clear it, right-click to flag one you think is a mine. Click an already-cleared number once you have flagged all the mines around it to clear the rest at once. On a touch screen, turn on Flag mode to tap-and-flag instead of tap-and-clear. Keyboard: tab to the board, arrow keys to move, Enter or Space to clear, F to flag. The very first cell you clear is never a mine. Your game is saved in this browser, so you can close the tab and come back to it.