Signpost
Follow the arrows to link every square into one path
Drag from a square to the square that follows it, or tap one and then another. Right-drag, or turn on Link backwards, to go from a square to the one before it. With the keyboard, arrows move, Enter starts a link from here and Space a link to here; press it again on the other square to finish, or Escape to cancel. X unlinks a square and Shift X its whole chain. Ctrl or ⌘ Z undoes; Shift Z redoes.
Progress saves on this device.
How to play
Link the squares into one path numbered from 1 to the last square. Each square’s arrow points toward the square that follows it; that square can be any distance away along the arrow. The first and last numbers are shown, and a few in between may be too.
Joining two squares gives them numbers: if one has a number, the other takes the next or previous one. Joined squares without a number yet carry a letter, such as a, a+1, a+2, and share a colour until they reach the numbered path. An arrow turns hollow once its square is linked to its successor, and a dot marks a square that still needs a predecessor.
Selecting a square lights up the squares it can link to. Dragging a square off the board removes its links; right-drag to remove the whole chain, or use Unlink and Unlink chain. A chain that holds a given number comes apart one square at a time. A ! marks a conflict. Solve reveals the answer and does not count as a win. Restart puts the puzzle back as it started, and Undo brings your moves back.
Puzzle by Janko (Pfeilpfad). Engine: Simon Tatham’s Signpost, contributed by James Harvey. MIT license and credits.