🔧 Pipe Flow
How to play
Pipe Flow is a plumbing puzzle with a satisfying payoff. Each level deals you a grid of scrambled pipe tiles, plus two fixed tiles: a valve marked IN on the left edge and a drain marked OUT on the right. Your job is to rotate the tiles — one click or tap turns a tile 90° clockwise — until the pipes form one unbroken channel from the valve to the drain. When you think you have it, press the big blue Test Flow button and watch the water run. If the stream reaches the drain, the level is yours; if it stalls, the tiles where the flow got stuck pulse red so you know roughly where to look.
Controls
- Mouse & touch: tap any pipe tile to rotate it 90° clockwise. Locked valve and drain tiles cannot rotate.
- Keyboard: use the arrow keys to move the amber highlight between tiles, then press Space or Enter to rotate the highlighted tile.
- T runs a flow test, R resets the board to the level's original scramble.
- Reset Board restores the starting layout, zeroes your move counter and restarts the level timer — handy when you have rotated yourself into a corner.
Tips & strategy
- Start at the valve and trace forward mentally instead of solving the whole grid. A path that begins correctly rarely needs to be rebuilt.
- Learn your fittings: straight pipes connect two opposite sides, elbows connect two neighboring sides. Every correct path is just straights and elbows chained together.
- Decoy tiles fill the grid to confuse you — ignore pipes that clearly head nowhere and focus on the corridor between IN and OUT.
- The par number is the minimum number of rotations the level needs. Matching par earns the full 1,000-point level bonus.
- Test the flow early and often. A failed test is free information: it shows exactly how far your current layout carries the water.
- On the 9×9 Expert board, fix one short section at a time and re-test. Small wins compound into a solved level.
Scoring
Each level starts at 1,000 points. Every rotation beyond par costs 10 points, and every five seconds beyond the first minute costs 1 point, down to a floor of 100. Finishing a level at or under par with a quick time is therefore worth the full thousand — and your three level scores add up to the final total shown on the completion screen. There is no penalty for a failed flow test, so test aggressively and chase the cleanest, fastest solve you can manage.