If you want to help, go ahead! Please remember that no Javasript is allowed.
Also, I would like to stick with a static CSS file, if possible.

Problems.
  - The game doesn't show well in many browsers.
  - The current way to set a flag is not very practical.

Nice desired features...
  - Detection of a won game:
    - sunglasses guy,
    - stop the counter,
    - lock the grid.
  - Equivalent to the middle-click in standard game: open all remaining boxes around a
    resolved number (for instance the number says '2' and you already found the 2 bombs,
    so middle-clicking on the '2' opens the remaining boxes around).