Material: Board, cone, 21 tiles per player (mainly black for one player, mainly yellow for the other)
Every player gets his tiles. The starting player additionally gets the cone.
On his turn a player must place a tile on a vacant spot on the board. If the player has the cone he may place a second tile. If he chooses this option he has to give the cone to the opponent.
The player with the black tiles wins when there is a continuous yellow area connecting the two yellow edges. The player with the yellow tiles wins when the two black sides are connected (so with every move you are helping your opponent).