Loop & Lantern

Click the rails between dots to draw or erase a line. Each number tells you exactly how many of its four sides belong to the loop. A 0 needs no lines.

Make one continuous loop, with no branches, loose ends or separate loops. Coral lines are unfinished; amber is a closed loop with clues left to satisfy; mint means solved.

Keyboard: Tab to a rail, then Space or Enter to toggle. Arrow keys move between rails. Z undoes. Progress saves on this device.