This is a two-player tactical game played on one phone.

You start the game with 100 seconds. On your turn, your time runs down. If your time runs out, you lose.

You take turns placing a stone on to the board. When you place a stone, if it makes a straight line of 6 or more of your stones, you win. Otherwise, the square of the number of stones your stone touches is taken from your time.

For example, if your stone didn’t create a winning line and touched 4 stones, you’d lose 16 seconds.

Making a winning line is very hard against a careful player with plenty of time - the trick is to make your opponent spend a lot of seconds blocking you.