Plumber

The brief fits in a single line. Pipe segments lie scattered across a grid; rotate each one until a continuous route runs from the source to the outlet. Simple rules do not make simple grids, though, because some pieces are elbows that force a direction and others are junctions that split the flow somewhere you did not want it to go.

Most people work forwards from the tap because that is the natural reading order. On a crowded grid, working backwards from the outlet is usually faster, since the outlet normally admits water from one direction only, which locks the piece beside it, which in turn constrains the next. Two or three deductions in, the remaining choices thin out until the whole route becomes visible at once.

Nothing here is strictly timed, so it is a game for people who enjoy sitting and thinking rather than clicking quickly. We shelve it under thinking at My Urban Eatery, next to the other logic puzzles that measure planning instead of reflexes.