Ouroboros
(Published on 1. October 2025, 14:16 by dingdongeu)
Choosing a circular/spiral theme, I tried to make an entertaining puzzle, and I think it came out quite nicely.
- Sudoku: Normal sudoku rules apply.
- Kropki: Cells joined by a black Kropki dot have a ratio of 1:2
- Thermometer: Along this line, digits strictly increase starting from the bulb.
- Killer cages: Digits in a cage must sum up to the digit in the top left (if given) and cannot repeat.
- Renban Line: The purple Renban line contains a set of consecutive digits in any order.
- German Whispers: Any two cells joined by a green line must have a difference of at least 5.
- Region Sum: For each line, digits have an equal sum for each box they pass through.
Play it on Sudokupad here.
Solution code: Column 8 and 9 in sequence.
Comments
on 13. November 2025, 01:47 by Zarlino
Seemed a fairly straightforward 1* to me (time 10'02" with very little head-scratching), and I'm someone who more often deviates up from the consensus than down when rating difficulty. Maybe Phistomefel was a shortcut (which anyone who has heard of it will recognize in the layout, so I don't think this is a spoiler), but why not use anything available, right? I didn't use all the clues and it wasn't clear to me why some of them existed, especially in box 8, but maybe there's something about the reason for the design and name that wasn't apparent to me. Anyway, many thanks for setting this enjoyable puzzle.
on 16. October 2025, 22:14 by truffen07
Entertaining indeed!
on 3. October 2025, 11:04 by Onyx
7:44, very nice puzzle, entertaining indeed, good job!
on 2. October 2025, 08:09 by Peteronium
16 minutes. There are plenty 1* puzzles which take me longer. Thx for sharing
on 1. October 2025, 20:06 by Zibl
Great puzzle, thank you!
on 1. October 2025, 19:14 by PinkNickels
Very nice! THanks for sharing with us. If I may, most solvers prefer a one line (one row or one column) solution. But, it is of course your decision. Glad you decided to share. Very fun solve.
on 1. October 2025, 15:08 by sujoyku
Thank you for the fun puzzle, dingdongeu!
