Water streams down from the top into a grid of empty boxes, connected by rotatable pieces of plumbing. The player's task is to rotate and rearrange the pieces so that all the boxes are filled up with water. This must be done quickly - the water will inevitably leak and pool at the bottom of the screen, then start rising upwards, drowning row after row of boxes as it does. The level must be finished before the water reaches the top. Pipe sections can have from one to four openings, and may be rotated individually or in groups of four (which is the only way to rearrange their position on the grid). Any additional leakage will make the water level rise faster, so open-ended pipes at the bottom or sides of the grid will have to be sealed off. A box full of water will turn a solid white; as soon as all remaining boxes are filled up, the game progresses to the next level, with a larger number of boxes to deal with.