Minesweeper, except the sign is keeping score.

Every time you hit a mine, the price of gas goes up and stays up. Clear the field and it holds where it is. It never goes back down.

• Left click opens a square. The first one is always safe.
• Right click plants a flag. On a phone, press and hold.
• Click a number with the right count of flags around it to open the rest.

Lose and the next board deals itself. Nobody is stopping you.