Secret Windmill
(Published on 29. July 2026, 14:28 by marty_sears)
Rules:
Normal sudoku rules apply.
If two digits have an X between them, they sum to 10. If not, they don't.
If two digits have a V between them, they sum to 5. If not, they don't.
No two digits on the yellow circle may be consecutive.
Solution code: Column 1 reading downwards
Comments
on 17. September 2026, 23:44 by samwdc
Facepalming at how long it took me to remember the negative constraint, great puzzle!
on 15. September 2026, 07:30 by GrouseHound
OMG completely forgot the negative constraint and got stuck for a ludicrous amount of time...
That's what I get for not reading instructions good enough! Very easy solve once I realized!
on 5. August 2026, 17:19 by ThymePass
I did not appreciate the art when I solved the puzzle. Very pretty!
on 5. August 2026, 15:47 by fishwithapipe
Simply lovely, but it took me also a long while to spot the points of interest.
on 3. August 2026, 09:13 by davidz32z
I really did struggle to even make progress on colouring for awhile. I can see why so many found it easy one star, but if you had a hard time anyway you're not alone!
on 2. August 2026, 20:48 by Klausku
Nice puzzle. I almost ran out of colours
on 1. August 2026, 16:52 by tylerrioux
Definitely the hardest puzzle I have finished so far. Beautiful and I feel I might have leveled up my brain after that one. Thanks, was a delight!
on 31. July 2026, 00:17 by bob
1 star??? I gave up after 40 minutes of fumblling. Maybe I need to give up the paper and use software.
on 30. July 2026, 23:03 by TomT
Missed the negative constraint for a bit. Used letters in place of numbers.
on 30. July 2026, 18:53 by GeorgeTheToad2
Amazed that solved!
on 30. July 2026, 17:10 by Jen118266
Some few puzzles deserve more than very nice. This is one of them ????
on 30. July 2026, 10:45 by bboom
Beautiful aesthetic, and it just gets prettier during the solve.
on 30. July 2026, 07:56 by pagedo
Very enjoyable.
on 30. July 2026, 06:23 by LunchEntity
Mmm, painty
on 30. July 2026, 02:46 by yuripuppies
Nothing like a good coloring puzzle! Thank you for another fun puzzle Marty
on 30. July 2026, 00:29 by sorryimLate
I assumed every domino that contains a V must sum to 5 etc. Nice puzzle!
on 30. July 2026, 00:25 by hamosphere
Under 10min 1* and I agree, very much in the style of Nuglesgift - love it.
on 29. July 2026, 22:57 by drbs
Nice puzzle, with an mechanical solving path. It reminds me of some easiers from NurglesGift. In XV puzzles with negative constraint I rather use letters than colours. AB and CD for the Vs and AE, BF, CG, and DH for the Xs. No need to remember which colours can‘t go together.
on 29. July 2026, 20:54 by damo_89
What's the secret? The windmill is right there in the grid.
Marty: ;)
on 29. July 2026, 20:14 by mrhayb
A superb puzzle Marty! Disambiguation was satisfying.
on 29. July 2026, 19:18 by CarnacTheMagnificent
Awesome puzzle. The disambiguation at the end was brilliant. Thanks for sharing.
on 29. July 2026, 18:31 by firespire
I love finding a negative constraint puzzle.
Always a surprise as you can't search for them because I don't know how to exclude the word "No" or "Not" from search results.
Wish you could search solver comments on here, I've never needed the search solution code description option.
on 29. July 2026, 17:51 by Nairurian
Nice puzzle, and always fun when you have a puzzle where you know where every number go before you know what those numbers are.
on 29. July 2026, 17:48 by blackjackfitz
Huzzah!
on 29. July 2026, 17:27 by mscha
Nice! For me a two-star rating, though, which makes me wonder if I missed something. (I got there, very systematically, in the end, but it took me about half an hour.)
Wow, 60 solves on LMD, 140 on SudokuPad, in 3 hours! I guess I'm not the only one obsessively refreshing Marty's LMD page. :-)
on 29. July 2026, 17:23 by IYelledataSquare
You have a way of making restraints and solving so whimsical and fun! Loved every second. Agree with others that it's a 1 star if you have experience; 2 star if not. Thank you, Marty!
on 29. July 2026, 17:17 by wuc
Brilliant marking puzzle. 1* maybe for solvers very used to all these constraints. To me clearly 2*. Great setting thx.
on 29. July 2026, 17:14 by macintux
I love coloring, I love negative constraints, and I especially love very fast solves. Thanks Marty!
on 29. July 2026, 17:14 by Franjo
Thank you very much for creating and sharing this lovely beginner’s friendly coloring puzzle.
on 29. July 2026, 17:13 by barnacle
Delightful color puzzle! I agree with the other commenter that it did feel a bit more 2 than 1 star, but enjoyable nonetheless. :)
on 29. July 2026, 16:16 by philolologue
Marty's puzzles are always oh-so-much-fun! Love a good colouring puzzle, and the constraints/disambiguation were a blast. The logic def feels like a 2-star difficulty to me at least, if 1-star is the more snack-level 1-5 min ones. Took me 30 min and 30 seconds flat.
on 29. July 2026, 16:00 by lizzzyc
Fun, beginner-level lettering puzzle. Fun disambiguation!
on 29. July 2026, 15:45 by superkinkel
Beautiful.
on 29. July 2026, 15:30 by highonlife
Smooth solve. Pretty Easy.
I would say , if you know how to use use colouring and letters in sudokupad, its very easy.
