Echo Chamber (Counting Circles + Cave Shading)
(Published on 24. December 2025, 04:32 by Allagem)
Normal Sudoku rules apply.
Cave Shading: Shade some cells in the grid such that all unshaded (cave) cells are orthogonally connected, all shaded (wall) cells are orthogonally connected to the edge of the grid, and no 2x2 is fully shaded or unshaded.
Counting Wallsweeper Circles: A digit in a circle indicates how many circles contain that digit. A digit in a circle also counts the number of shaded (wall) cells in the surrounding 3x3, NOT including itself.
Cave Sums: A small number in the corner of a cell gives the sum of all digits seen orthogonally from that cell, including itself, where cells of the opposite shading block vision.
(with a clean solve path!)
I hope you enjoy my latest puzzle, Echo Chamber!
Solution code: Digits on shaded (wall) cells in row 6.
Comments
on 25. December 2025, 19:19 by Snookerfan
Brilliant puzzle, thanks!
on 24. December 2025, 11:45 by Bankey
Fun puzzle. Thanks, @ Allagem :).
on 24. December 2025, 10:14 by Piatato
Cool!
on 24. December 2025, 08:27 by Visumation
Very cool. Thanks
on 24. December 2025, 04:38 by Andrewsarchus
The combination of cave and counting circles leads to some very cool logic! Fun puzzle.
