Two players sit at opposite ends of the modular game board. Simultaneously, the players place marbles from the tray on their side of the board into the drain pipe in front of them. As their opponent's marbles roll down the gutter towards them, players try to keep the marbles from landing in their personal drain cup by pressing down on bellows. The bellows activate various mechanisms along the marbles' path which can knock the marbles into a different gutter that instead leads back into the tray. The game ends when all the marbles have landed in the drain cups. The player with the least marbles in their own drain cup wins.