Lost and Found: A massive collaboration puzzle
(Published on 27. November 2025, 20:54 by Jeet Sampat)
Co-created by (in order of contribution): Jeet Sampat, Myxo, dumediat, damasosos92, Agent, SSG, glum_hippo, Playmaker6174, tallcat, Malrog, mnasti2, Piatato, Christounet, MaizeGator, sfushidahardy.
A couple of months ago, I sent an empty grid to Myxo with a weird "almost Sudoku" rule-set, and asked him to add at most one line of rule and at most one clue to the grid. Myxo would then send it to someone else with the same requirement and so on until the grid achieves a unique solution. This is the outcome of this project and I am quite pleased with the results. I hope you enjoy it as much as we enjoyed making it!
The difficulty is between 3* and 4*, with the toughest part being scanning the grid.
Rules:
Almost Sudoku: Fill the grid with digits 1-9 so that each row, column, and box contains exactly 8 unique digits.
Arrows: Digits along an arrow must sum to the digit in the attached bulb.
Slow Thermometers: Digits along a thermometer must not decrease from the bulb end to the tip.
German Whispers Line: Two cells connected by a green line must have a difference of at least 5.
Skyscraper Clues: Clues outside the grid give the number of digits visible from the clue's position, given that each digit blocks the view of any digits behind it that aren't larger than it.
Region Sum Lines: Along a blue line, box borders divide the line into smaller segments with the same sum. Digits can repeat along a segment if allowed by other rules.
Try it on Sudokupad.
Puzzle:
Solution code: Column 5 (top to bottom); 9 digits, no spaces.
Comments
on 3. December 2025, 15:31 by QuiltyAsCharged
Brilliant! I'm torn between hoping to encounter more "almost sudoku" puzzles soon, and hoping to give my brain a rest :)
on 2. December 2025, 03:04 by konklone
I loved this, especially the final clue - what a great touch that was. Very cool idea from some very cool setters =)
on 1. December 2025, 13:50 by Nightmare2805
That was fantastic
on 1. December 2025, 08:43 by antiknight
Loved the beginning of the puzzle it had a great flow, but it definitely became mind bending in the middle and toward the end.
on 1. December 2025, 04:36 by Crusader175
Very nice!
on 1. December 2025, 02:59 by damasosos92
It's a joy to be part of this project! Thanks Jeet for this opportunity <3
on 1. December 2025, 01:08 by v8nagrom
What the **** was that?! :D
Truly an amazing puzzle. Thanks to you all.
on 30. November 2025, 22:52 by sfushidahardy
Pleasure to be a part of this! I was amazed at how well everyone made the clues interact, when all we could do was place them one at a time.
on 30. November 2025, 17:35 by SSG
This was an absolutely mind-bending puzzle to work on; and, I'm thrilled it came out so well.
on 30. November 2025, 16:07 by davidemsa
The almost sudoku fried my brain, but it makes for very interesting deductions.
on 30. November 2025, 12:30 by Exigus
That was hard but totally amazing. Thanks!
on 30. November 2025, 09:23 by Malrog
It was a joy to be part of this, and really fascinating to see how it turned out. Great idea Jeet, and I'm very proud of my fellow setters for producing something that's both aesthetically and logically interesting.
on 30. November 2025, 07:39 by XuanZzz
Excellent puzzle! My brain was totally messed up. Agreed that the rating should be higher
on 29. November 2025, 21:55 by Christounet
Well, we all know why the rating started so "low"...
on 29. November 2025, 20:51 by Jeet Sampat
I wouldn't say 92% is a low rating... at least it shouldn't be considered low :)
on 29. November 2025, 18:37 by Blake Saligia
The clues are interlinked and work together perfectly! I don't understand why the rating is so low
on 28. November 2025, 19:47 by little_turd
May cause serious brain injury. Still, would do it again.
on 28. November 2025, 09:41 by Snookerfan
Great puzzle! Mindbending and fun, thanks to all of you!
on 28. November 2025, 03:21 by rameshsrivats
My brain is in knots. What a crazy puzzle! And what fantastic setting! Joy all the way.
on 28. November 2025, 00:36 by bansalsaab
Crazzy
on 27. November 2025, 23:26 by Christounet
It was a very unique experience to be a part of this and add my little brick to the construction! Thanks Jeet :)
on 27. November 2025, 23:08 by Piatato
I had fun being a part of this project! Happy to see how it turned out in the end!
