Wrap around: pipes that cross the edges

Here the board has no edges: the left side is joined to the right one, and the top to the bottom. A pipe that leaves on one side comes back on the other, so any tile can point any way.

Without edges there is no easy start: the first move already needs a real insight, and every insight opens up more of the board. Turn the mode off or on for any size with the “Wrap around” switch in the menu.

Rules

Click a tile to rotate it. The puzzle is solved when the pipes form one network from the pump to every lamp, with no pipe pointing at nothing and no closed loop. Water shows how far the pump reaches, and the counter above the board shows how many lamps are lit.