Duskrow

Duskrow is a free daily lights-out logic puzzle with forty levels in front of it. Every night the same street appears for everybody, some of its windows are still burning, and your job is to put the whole row out. One puzzle a day, a streak for coming back, and a small result you can paste to a friend.

It opens on the levels rather than the daily row, because the rule is easier to meet one piece at a time than all at once. Level one is three lit windows in a row, one shape, one tap — the answer is visible before anything is explained. After that each step adds exactly one idea: two taps that overlap cancel each other where they meet, a shape at the edge is cut short and flips fewer windows, a second shape means the first real choice, and then a window with somebody still in it who is not going anywhere. The forty levels walk through four streets — Canal Street, Brick Lane, Snow Hill and Lantern Row — and each street opens with a new shape or a new rule. By the last one you are playing the same three-shape choice the daily row uses, and the daily row is no longer confusing.

A tap is not a switch, it is a stamp. You pick one of the night’s three shapes first — a streetlamp cross, a terrace of three, a stairwell, a gable, a crossbeam, a whole floor — and tapping a window flips every window that shape covers. Lit becomes dark, dark becomes lit. That is the entire rule, and it is also the entire difficulty: turning one window off usually turns two others on, so the puzzle is about finding the small set of stamps whose overlaps cancel.

Two details keep it from being mechanical. Shapes are cut short at the edges, so the same stamp in the middle of the row and the same stamp in a corner are genuinely different moves — the corner one flips fewer windows, and that asymmetry is often the key. And some windows have somebody still in them: they stay lit no matter what, they never flip, and every shape that touches one quietly does less than it looks like it should.

Par is measured, not guessed. Before the night is served the game searches for the shortest possible route through that board and shows you the number. Finishing on par means you found the best line there is. Finishing under it means the search missed something and you did not, which is the best thing that can happen to you here.

The board is built by stamping an empty street, which means every single night is solvable by construction — there is no night where the street cannot be put out. Tapping the same spot with the same shape takes a stamp straight back, two Undos per level are free, and older rows can be replayed as practice without touching your streak.

It plays with one finger on a phone or a mouse on desktop. No download, no account, nothing to install.

Pick one of the night’s three shapes, then tap a window. Every window the shape covers flips — lit goes dark, dark goes lit — and the goal is a street with nothing burning. Tap the same spot again to take it straight back, or use Undo. Two things make it a puzzle rather than a chore. Shapes are cut short at the edges, so the same shape is a different move in the middle of the row than it is in a corner.

And some windows have somebody still in them: they stay lit, they never flip, and every shape that touches one quietly does less. Par is not a guess — the game searches for the shortest possible route each night and shows you that number, so finishing on par means you found the best line, and finishing under it means you found one we did not.

Start with the 40 levels: the first one is a single tap with a single shape, and each step after it adds exactly one idea — taps that cancel where they overlap, shapes cut short at an edge, a second shape to choose between, a window with somebody still in it. By the last level you are playing the same street the daily row uses. Then there is one puzzle a day, the same one for everybody, and a streak for coming back.

Older rows can be played as practice without touching the streak.