Flow free,
no path crosses another.

Flow Free is a path-connection puzzle. The board has pairs of colored endpoints; your job is to draw a path between each pair so the colors never cross and every cell on the board is covered when you're done.

Press and hold on any colored endpoint, then drag across adjacent cells to draw that color's path until it reaches its partner endpoint. Drawing through a cell that already belongs to another color pushes the other color back — it does not stack. Release when the path is connected, then start a different color.

You win when every endpoint pair is connected by a continuous path and every cell on the board is covered. Connecting all the pairs without filling every cell is not enough; the percentage indicator in the toolbar shows how close you are.

Not strictly — uniqueness enforcement is a v2 follow-up. Each puzzle is generated by cutting a Hamiltonian path across the grid into colour segments, so a valid solution always exists by construction and the convoluted shape makes alternate routings rare in practice. Some boards may still have more than one valid completion; any routing that fills every cell without crossings counts as a win.

Easy is a 5×5 grid with 4 color pairs, Medium is 7×7 with 6, Hard is 9×9 with 8. Larger grids and more colors mean more pieces to coordinate; the same "fill every cell, no crossings" rule applies at all sizes.

Tap a color's endpoint to start a new path from there — the old path resets automatically. Or drag backwards along a path to truncate it cell by cell. Either way you can rework a color without disturbing the others.

The endpoints use the warm Letterhead palette — clay, moss, lilac, sky, peach, sage, amber, plum — so the board reads as one family. No saturated rainbow primaries; the puzzle is the point, not the colors.

Every endpoint also carries a number from 1 to 8 inside the circle, so colours are identifiable independently of hue. Same idea as the original Numberlink puzzle Flow Free is based on — the numbers are the primary cue, the colours are the secondary one.

Yes — touch and drag works the same as mouse drag. The board scales to 480px wide and respects safe-area insets on iOS so endpoints stay reachable.