When the orange number is 1, that means that you can click on tiles to make them alive. If a block has less than 2 or more than 3 neighbors, that means it will die next turn. If it has 2 or 3 neighbors (anything more or less will not suffice), it will survive. If a dead tile (red) has 3 neighbors, it will be resurrected. Press space to advance to the next turn.