private bool CheckForWin()
{
bool bWon = true;
for (int col = 0; col < columns; col++) {
for (int row = 0; row < rows; row++) {
Tile tile = tiles [col, row];
if (!tile.isMine() && !tile.isUncovered()) {
bWon = false;
break;
}
}
}
gameWon = bWon;
return bWon;
}