The Riverbank

One continuous board. Finish the face you're on and it grows six rows higher — your corner block becomes the cornerstone of the next face. Ordinary rules, always.

Hold a square and drag: a ring of digits blooms under your finger.

No account. Your climb lives in this browser.

Flat ground instead? hike.sudoku.tony.win

Forest recorded on an Amazon riverbank by Félix Blume (CC0).