This puzzle is a creek puzzle with variant rules:
Shade some cells in the grid so that all non shaded cells are connected and no 2x2 region is fully shaded or non shaded. The number in each circle indicates how many shaded cells there are in the 4 cells around it.
Solution code: The solution is the number of shaded cells in columns 4, 6, 8, and 10, without spaces.
on 27. February 2023, 21:36 by actinide
Provided german translation
on 28. November 2022, 11:26 by professorX
Smooth solve path ...
on 11. September 2022, 05:17 by jovi_al
trickier than 1/5 in my opinion, but nice puzzle :)
on 10. September 2022, 00:47 by Rollo
Nice little puzzle :-).
on 9. September 2022, 18:58 by actinide
Lowered the estimated difficulty