Dutch Flat Mates: Ziffers
(Published on 17. September 2025, 07:00 by marty_sears)
Rules:
Normal sudoku rules apply.
DUTCH FLAT MATES: Every 5 in the grid has a 1 directly above it or a 9 directly below it. It may have both, but it doesn't need both.
ZIFFERS: Any pair of cells that are an equal distance from the central spot of a coloured ziffer line have a difference equal to the digit on that central spot.
Solution code: Row 6 from left to right
Comments
on 7. January 2026, 15:06 by giusb
Got stuck a couple times missing easy digits. There's more sudoku in this sudoku than I expected I guess! Very fun puzzle though
on 6. October 2025, 14:50 by stickx
Thanks Marty! Got stuck at the end as well, but there weren't too many moving parts at that point, so it was findable for me.
on 19. September 2025, 01:28 by KillerCard10
I loved the interaction of the two mechanics! Great puzzle.
on 18. September 2025, 18:25 by npinguy
Loved the breakin in that one column, but after that I desperately wanted this to work as a colouring puzzle and kept getting frustrated it wouldn't.
Because I forgot about the dutch flat mates. They always get me! I can never remember with them that when you get stuck, "go check in on those 5's". (and when i do, everything unblocks again)
on 18. September 2025, 14:27 by Black_Doom
Really lovely, and not too contrived at all :)
on 18. September 2025, 01:19 by softie
That was nifty.
on 17. September 2025, 22:52 by vitaminz
Really lovely break-in. I almost whoopsied by it until I saw that my starting inference absolutely had to be incorrect based on the other elements of the puzzle.
on 17. September 2025, 22:17 by sujoyku
Wonderful puzzle! Thank you, Marty!
on 17. September 2025, 11:40 by Franjo
There was only one last step that was a bit tricky for me, but all in all the path was smooth. Thank you very much for creating and sharing this lovely DFM-puzzle.
on 17. September 2025, 10:48 by mscha
Very nice interaction between the ziffers and the flat mates. The break in is very elegant, but not too difficult if you've seen ziffers before.
I ziffed through the puzzle until the endgame, where I got stuck for a while missing an obvious digit.
on 17. September 2025, 10:41 by richcard
Lovely puzzle that "zips" along nicely. Whenever I felt like I was running out of steam, there was a friendly flatmate to nudge me along again.
on 17. September 2025, 10:23 by marcmees
easy & fun. Thanks
on 17. September 2025, 10:21 by Flinty
Lovely stuff. :)
And so much easier if you don't repeatedly drift into Zipper logic and wonder why you keep breaking it - haha.
