Very nice readable source code.<p>One feature request I'd have is allowing users to skip flags. I usually play minesweeper fast and don't set any flags. The game should end when I opened all fields without hitting a bomb, at least that's how others minesweeper implementations work (e.g. <a href="https://www.google.com/fbx?fbx=minesweeper" rel="nofollow">https://www.google.com/fbx?fbx=minesweeper</a>). Maybe<p>if (num_revealed = x*y-num_bombs) Mine.over = true<p>The google one also seems to guarantee that the first click opens a whole field, never just one number or bomb. Not sure how they do that but it make the game more enjoyable.