Gamehelpminefield

Minefield is an OOSCG (Orthogonal Only Square Connection Game). You have to form an orthogonally interconnected path connecting the two board edges of your color. The game is presented like this and can certainly be played like this. But, once you have formed an ortho-diagonal connecting path, your opponent will not be able to do the same, and there's nothing to stop you from going back and filling in the diagonal connections, converting them into orthogonal connections. So you've essentially won upon forming an ortho-diagonal connecting path. In the BGA implementation, the developer chose to end the game at this point - a decision I agree with.