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Drag a single unbroken line through checkpoints 1 through N, covering the whole board.
Draw a single unbroken line through every cell on the board, moving only up, down, left, or right — no diagonals, no crossing over yourself, no branching.
Numbered checkpoints must be visited in ascending order: 1, then 2, then 3, and so on, at whatever point the line happens to pass through them.
Drag from the starting checkpoint to draw the line, cell by cell. Drag backward over the line you just drew to erase those cells and correct a mistake — no need to start over.
Cells that break the checkpoint order are highlighted so you can spot the problem. The puzzle is solved once the line covers every cell exactly once with all checkpoints in order.
Hint reveals the next correct cell but counts against your score. Practice mode lets you pick a 5×5 or 6×6 board and any difficulty. The daily puzzle is a 5×5 board everyone plays together.