Chain Sweep: Block Fill Line

One unbroken line through every square. Works offline, no timer, no lives.

Chain Sweep is one line, drawn without lifting your finger.

Press the start dot and drag. The line follows you through the grid and has to reach the goal dot having passed through every open square exactly once - none missed, none used twice. Drag back along the line you have drawn to rub it out and try another way.

HOW TO PLAY
- Press the start dot to begin
- Drag through the grid; the line follows your finger
- Every open square has to be used, and none of them twice
- Drag backwards along your own line to erase
- Reach the goal dot with the board covered

THE PUZZLE IS AT THE END, NOT THE START
Almost any first move looks fine. The trouble arrives four turns later, when three squares are left in two different corners and nothing can reach both. So a path that covers everything usually has to be found from the finish backwards - and learning to see that before you commit is the whole skill.

NOTHING TO LOSE
No timer, no move limit, no lives, no way to ruin a board. A wrong turn is not punished; it is retraced. Put the phone down mid-line and it is exactly where you left it.

WHAT YOU GET
- Hundreds of levels, from small open grids up to boards with walls and gaps
- A hint that draws the next few squares of the solution for you
- A daily challenge: one board, the same for everyone, every day
- Fourteen colour sets and twelve board designs to unlock as you play
- A level map, to go back for the ones you brute-forced

PLAYS ANYWHERE, ONLINE OR OFF
Works offline with no wifi. Small download. No account, no sign-up, no personal details asked for. Your progress stays on your own device.

Chain Sweep is free and supported by ads. You can watch an ad by choice to earn extra hints, and coins you earn by playing unlock the colours and boards. There is nothing to buy.