Water flows from the top into a grid of empty boxes, connected by rotating plumbing pieces. The player's task is to rotate and rearrange the pieces so that all the boxes fill with water. This must be done quickly, as the water will inevitably leak and pool at the bottom of the screen, and then begin to rise, drowning row after row of boxes. The level must be finished before the water reaches the top.
Pipe sections can have from one to four openings, and can be rotated individually or in groups of four (which is the only way to rearrange their position on the grid). Any additional leakage will cause the water level to rise faster, so open pipes at the bottom or sides of the grid will have to be sealed. A box full of water will turn solid white; as soon as all remaining boxes are filled, the game advances to the next level, with a greater number of boxes to contend with.
