Runnel — Pipe Flow Puzzle

The reagent is already pouring. It will not wait.

Runnel is a pipe flow puzzle built around one idea: the liquid never stops. You drag glass pipe from a queue and lay it ahead of the leading edge, deciding where the flow goes a second before it gets there. Take what you are given — pieces cannot be rotated — and make the route work anyway.

TWO WAYS TO THINK

The Ledger — 50 levels with no clock. Every level deals a fixed crate of pipe, so the puzzle is what you spend it on. Plan the whole route before you start the pour, or lay it under pressure. Three stars for a clean, efficient run.

Blueprint — 50 more levels, and a different kind of pipe puzzle. Each one deals exactly the pieces its solution needs, in order. Nothing spare. Fill two or three flasks at once, obey the chapter's rule, and use every piece you are handed. Three hints per attempt when a board stops making sense.

Endless — an unbounded workbench and one question: how far can the liquid run? Splitters, valves and reservoirs unlock as you build.

Daily — one board, one attempt, the same for everyone. Save your result as a code, paste a friend's back in, and race their ghost along the same pipe line.

WHAT MAKES IT HARD

Three spills and the run is over — and a spill is not a life lost, it is a ratchet. Every one of them speeds the flow up permanently. Pipe wears out: a straight carries the liquid once, a cross twice, and spent pipe looks spent. A splitter divides the flow and then both branches must be fed for the rest of the run. Purge the route you have not used yet to buy the speed back, if you can afford to lose the lead.

THE WORKBENCH IS YOURS

43 things to unlock across five shelves — reagents that change the colour of the liquid, glassware finishes with real fittings, bench surfaces from oak grain to a star chart, collection vessels and spill effects. Most of it is earned by playing or by choosing to watch an ad, and a few pieces are sold outright if you would rather not wait. What is never sold is progress: all 100 levels play exactly the same whether you have spent anything or nothing.

• 100 proved levels across two campaigns
• An unbounded board you can pan and zoom
• A daily puzzle with verifiable results
• 20 achievements and rotating missions
• 1x, 2x and 4x pour speed
• No account, no sign-up — your progress stays on your device
• Left-handed layout, reduced motion, and a tablet layout that uses the space

Runnel is free and supported by ads. A runnel is the small channel cut to carry water — which is exactly what you are building.