Sudokuvania: Digits of Despair by Skeptical Mario
Every 100 years, the mysterious castle of Sudokuvania appears in the countryside. Legend has it that it contains the Secret of Sudoku. Gathering the last few given digits in the area, you solemnly approach the boxy fortress, determined to discover the secret and share it with your favorite people.
NOTE: You can now upgrade to the current version (v1.1.1) while keeping your progress. Please see the FAQ below for details.
This is a labor of love combining sudoku with my favorite video game genre - Metroidvanias. MVs are known for featuring exploration, gaining new abilities, and difficult boss fights, and I noticed the similarity to grid-based puzzles as soon as I started setting them. So, I present Sudokuvania: Digits of Despair.
Not just a big puzzle, Sudokuvania is a puzzle hunt in and of itself. As you clear the 40x50 map of dynamic fog, you will uncover new clues and new rules. Some cells' contents can only be found by solving linked Boss Puzzles. There is even a bit of a story, although I wouldn't call it compelling by any means. All in all, Sudokuvania is over 20 puzzles in one!
Note: Due to the size of the puzzle, it is best played on a desktop browser (SudokuPad does not currently support zooming in mobile). Make sure the setting "Experimental > Test Large Puzzle UI" is ON (the bottommost setting option in the menu).
To zoom, use the mouse scroll wheel or, on a Mac, two fingers on the touchpad.
A note on the difficulty: Do not assume that the provisional 5/5 is due to the size/length alone.
Rules:
Gattai Sudoku - In each square grid, enter digits from 1-N into each row, column, and region, where N is the length of each side of the grid.
Dynamic Fog - The map is covered with fog. Placing correct digits may reveal more clues or rules.
Clues may only be used if their associated rule is uncovered in the Learned Rules panel (in the upper left).
Dynamic Rules - Selecting cells can change the rules displayed by the puzzle; to avoid spoilers, only select cells which have already been uncovered from fog.
* Select a cell in the map to learn more about its grid, and to get a link to its Boss Puzzle (if applicable).
* Select a rule in the Learned Rules panel for more details.
Play the puzzle on Sudokupad (desktop only)
Read the player's guide and FAQ
I hope you enjoy the puzzle! :-)
Immense gratitude to sirxemic and Sven Neumann for creating the tools that made it possible for me to set this puzzle; special thanks to cirne for their json post-processing script which enabled the dynamically-updating rules; and everyone who tested and gave feedback during the months of development.
Lösungscode: The nine Boss Cell digits in grid order, followed by row 2 of the Throne Room grid (use - for empty cells)
Heute, 03:55 Uhr von konklone
I may never be more proud of solving any puzzle in my life, than this one. This is as many or more hours as SotN or any SotN-like game you could find, for $0 and at consistent high quality (and challenge!) throughout. Thank you for making this, and I hope you are proud of it.
am 19. Juli 2025, 19:14 Uhr von Pfanni
Almost 30h of fun and puzzeling for 2 people. Thank you so much for this amazing adventure!
am 17. Juli 2025, 14:55 Uhr von Jewel
Thank you so much!! This was some of the most fun I've had in years, I don't really play many sudokus but I had to try it after being recommended it and I managed to finish it (even though it took 80-90 hours!!) while being addicted pretty much nonstop. Incredibly cool stuff and really opened my eyes to what's possible and makes me want to find and play a whole lot more cool stuff, thanks for making what's clearly a deep love letter!!
am 14. Juli 2025, 00:07 Uhr von standgale
Hi, this is my first time using this website. Just came here to do this puzzle. How do I save progress?
am 13. Juli 2025, 00:41 Uhr von amelenty
Absolutely loved this! It took me almost 47 hours (this was, in many aspects, my introduction to variant sudoku :D) and the hint from ReliaRobot below (thanks!). This was hands down the most fun I've had in a while, and I was amazed at how well it captured the spirit of a Metroidvania, including how you come across all sorts of clues that don't make sense until halfway through the game. Thank you so much for creating this!
am 10. Juli 2025, 09:29 Uhr von Doodles
I've encountered a problem; Boss Cells appear as empty cells, with no Imp Emoji to mark them.
EDIT:
Disabling "Outlines on Elements" fixes this issue (and, as per @Zeddecks, comes with a free performance boost). Perhaps this should be added to the list of suggested settings in the ruleset
am 27. Juni 2025, 00:20 Uhr von thoughtbyte
Wow, this was clearly a labor of love and you pulled it off amazingly. Thanks so much for this, hats off to you.
am 25. Juni 2025, 18:01 Uhr von MDLucifer
This is so cool, bro(although it took me 1293 minutes to solve it)
am 17. Juni 2025, 11:44 Uhr von Mirrorstar
very good puzzle!
am 12. Juni 2025, 03:17 Uhr von dalestan
I found a minor bug in the Wolf puzzle in v1.1.1:
Turn on "check pencil marks", and fill the 15 non-given squares with pencil marks for 1234. The squares on right half of the puzzle correctly have red pencil marks where they conflict with the given digit (alternatively, the puzzle-unlocking digit), but the pencil marks on the left half are all shown in blue, even when they conflict.
am 31. Mai 2025, 20:41 Uhr von Zeddecks
Interesting times we live in where you can turn Sudoku into a game engine.
This was such a neat experience. Thank you for constructing this.
am 31. Mai 2025, 20:05 Uhr von Zeddecks
Another performance boost is to disable "outlines on elements". I found that to have a bigger impact than disabling conflict checker.
am 27. Mai 2025, 15:36 Uhr von ReliaRobot
Ah, I didn't know that there was a letter tool in the options you could turn on. That was a great puzzle! I thought that the hall of illusions was a little frustrating, but the rest of it was extremely good! There were some very clever moments, I never thought that I'd laugh out loud on a sudoku puzzle. This was truly excellent!
am 27. Mai 2025, 05:17 Uhr von ReliaRobot
I've solved everything but the title, and I could really use a hint. I'd love to see the text for really finishing the puzzle (and the code I entered here indicates that I did in fact solve it). I can see some options for how I MIGHT solve it, but everything I try is rebuffed by the checker. Can you add something to the FAQ document to help me out?
am 26. Mai 2025, 06:26 Uhr von Phase Queen Rachel
Finally finished this sudoku after 30+ hours of solving.
Amazing solve and loved working through all of it. Definitely the hardest sudoku I've ever solved.
am 24. Mai 2025, 02:17 Uhr von davmillar
Fun! Sequel? :)
am 21. Mai 2025, 00:18 Uhr von echo231
Really fun
Took 3 of us several weeks to fully solve
Incredible blending of genres
am 19. Mai 2025, 21:13 Uhr von Frank Puzzles
I solved this just recently.
Here's my introduction to the puzzle:
https://youtu.be/IUPNbZHGNDQ
I will be posting a video of part of my solve daily until I finish.
am 17. Mai 2025, 19:12 Uhr von unction
Thank you so much for making this, SkepticalMario, it was absolutely incredible. 2 people and over 50 hours later, we did it!
am 17. Mai 2025, 17:15 Uhr von opheliabedelia
Incredible game. I entered the digit for the grid 9 boss and nothing happened or changed on the board; is that a glitch?
---
Mario:
Entering that digit should reveal the next step; try checking your progress with the Check button?
---
Aha, the check button says everything was correct but I was missing a digit on the zipline. Looks like I have it now!
am 16. Mai 2025, 05:07 Uhr von dalestan
I've filled in C1 of Illusions from Battlements (with a 28 and 14 pair), and R9C9, but that hasn't revealed the special rule for Illusions. (Cheating with the solution checker to fill C1 also doesn't reveal the rule.)
Am I supposed to be able to make more progress without knowing the rule, am I supposed to be able to get more digits in Elsewhere than those given by Fillomino, or have I run into a soft-lock?
EDIT: It's not a soft-lock; I got past this with more thinking and/or sleeping.
am 14. Mai 2025, 01:44 Uhr von SkepticalMario
Sorry, there is a bug in the current version of SudokuPad which prevents the Boss Puzzle links from being clickable. Nothing I can do about it, but Sven is aware of the issue. I will delete this comment when it is fixed.
am 10. Mai 2025, 19:07 Uhr von illegel
excellent puzzle, absolutely art
am 9. Mai 2025, 15:07 Uhr von Christounet
What a long and enjoyable solve !
Progressing through the different rooms of the castle certainly reminded me the hours I spent exploring Zelda's map on my Nintendo NES when I was a kid. A journey full of fun surprises too. Incredible work putting this together and making work properly ! Thank you for this creative puzzle. Hopefully we'll get a sequel at some point in the coming months :)
am 9. Mai 2025, 02:15 Uhr von Nell Gwyn
Finally done! And wow, what an amazing adventure.
am 7. Mai 2025, 03:43 Uhr von TheGrand547
Overwhelming
am 30. April 2025, 05:50 Uhr von SkepticalMario
Updated to v1.1.1:
- Tweaked entry to two hidden puzzles
- Removed a couple more ambiguities outside the grid.
- Fixed bug causing checkmark on hidden puzzle to appear early.
This may very well be the last update. Thank you again for your patience!
am 29. April 2025, 07:27 Uhr von EvilClown13
Absolutely astonishing puzzle. I've never felt more challenged or more proud of myself playing any sort of game. This is a work of art and I feel lucky to have gotten the chance to solve it!
am 27. April 2025, 18:04 Uhr von IWannaFans
Finally solved, it took me 30+ hours and it was a perfect puzzle for me.
am 26. April 2025, 13:38 Uhr von pentadream
excellent puzzles, I recorded all my playthroughs on bilibili, you can take a look of them if you meet some obstacles
am 26. April 2025, 06:18 Uhr von MonicaLAM
Q: Upgrading from v1.0.2 to v1.1.0, I noticed that a wall food outside of grid 9 was removed. Was this intentional?
A: Yes, I hadn't realized how much adding that food affected the solve path.
am 25. April 2025, 06:21 Uhr von SkepticalMario
Updated to v1.1.0 - the last update for a long time, I hope.
-Finishing the grid NOW ACTUALLY clears all fog.
-Tweaked fog path to be more intuitive in several places.
-Added upgrade URLs to the FAQ.
am 24. April 2025, 06:25 Uhr von aqjhs
my maximalist self incommensurably rejoices
am 24. April 2025, 04:21 Uhr von SkepticalMario
Updated to v1.0.4:
- Fixed bug in 1.0.3
- Clearing final grid now clears all fog
- Additional rule clarifications
am 23. April 2025, 22:03 Uhr von SkepticalMario
Rolling back to v1.0.2 because of the issues dvorak42 noticed. Will update to 1.0.4 within 24 hours, with proper testing this time
am 23. April 2025, 20:04 Uhr von dumediat
After about 23 hours of solving (100% clear), I simply lost count of the number of beautiful steps I found along my journey. Difficulty ranges from "Animal Crossing" to souls-like, and there is certainly something for everyone in this masterpiece. Thank you so much for bringing this to us! :D
am 23. April 2025, 17:44 Uhr von kamkam
JUST WOW. This took me hours and hours, and it was absolutely divine. Maybe my all time favorite puzzle :-)
Maybe a little thing to improve the game: if everything is unlocked, why not clear the fog everywhere, even where there are blank spaces ? Quite frustrating to still see some grey covered cells :-p
(and what did the battery and the ❗️ meant ? ahah)
am 23. April 2025, 15:50 Uhr von dvorak42
There appears to be an issue with v1.0.3, where entering the correct digit in R3C3 of grid 8 doesn't remove any more fog, while in v1.0.2 it did.
---
You are correct, I've quickly fixed this and updated the TinyURL link. The new code for v1.0.3 is 9ebjb05id4.
am 22. April 2025, 02:25 Uhr von SkepticalMario
Updated to v1.0.3:
- Removed more ambiguities
- Clarified some boss puzzle rules
am 18. April 2025, 15:51 Uhr von MonicaLAM
In a fit of overexuberance, I wrote a walkthrough for boss 7. (It started as my own solving notes and got out of hand.) I could potentially post it somewhere if there's interest.
am 17. April 2025, 02:37 Uhr von SkepticalMario
Updated link to shortened TinyURL which contains the Large Puzzle UI parameter
am 11. April 2025, 18:34 Uhr von CutieRainbow
I spent 30 hours to solve this sudoku.
am 10. April 2025, 23:15 Uhr von SkepticalMario
Updated to v1.0.2:
Fixed a couple ambiguities
Added tutorial quest step for outside the boxes
am 7. April 2025, 05:16 Uhr von RJBlarmo
This was a really fun experience, and some of the puzzles are genuinely quite difficult! I appreciate the insane amount of time and effort that must have went into creating this.
I did encounter some ambiguities during my solve but nothing that detracted from my enjoyment of solving this. Really impressive creation!
am 7. April 2025, 04:53 Uhr von SkepticalMario
Updated puzzle to v1.0.1:
Fixed broken sidequests
Changed solution code
am 6. April 2025, 15:04 Uhr von SkepticalMario
Sorry about the lack of replies; I had a long shift yesterday.
I am going to update the puzzle and the FAQ with everything in the next couple of days.
am 6. April 2025, 12:09 Uhr von puppyvardy24
i solved also all zipper lines but it wont give me a green vink
am 6. April 2025, 11:24 Uhr von puppyvardy24
and in what software progamma dit you make this one
A: I used dev.sudokumaker.app to create the puzzle and export it to SudokuPad.
am 6. April 2025, 11:08 Uhr von puppyvardy24
i have solved all grids but i am stuck now
because i have everithing filled in their is only a white squer beneath the box grids box
am 5. April 2025, 17:31 Uhr von SkepticalMario
Added link to FAQ
am 5. April 2025, 16:57 Uhr von SkepticalMario
I'm making the FAQ now.
am 5. April 2025, 16:02 Uhr von jinkela114514
Q: Are there some ways to improve the performance of the puzzle page?
A: To improve performance, it might help to turn off conflict checking and the killer cage calculator. I will continue to collect data on this.
Q: Other potential actions that might lower the performance of the web page include the following things; selecting different grids, clearing fog, double clicking digits, and so on.
am 5. April 2025, 15:35 Uhr von puppyvardy24
i have a great question i am verry far but i am stuck i dont know what to do can you send me your email or number so i can get further ??
am 5. April 2025, 13:48 Uhr von jinkela114514
Q: How did you achieve the clicking things?
A: There's a metadata property in the puzzle JSON that assigns regions of the grid their own rules. I believe Sven added it to support collaborative multipuzzles like the Caterdokupillar.
am 5. April 2025, 09:17 Uhr von ndsurgenor
As far as I can tell, any new element which appears shouldn't be used until the rule has been revealed.
I had a Kropki appear yesterday and started using as per it's normal rules then realised those hadn't been established; cue minor panic as I realised that I might have to backtrack as I had assumed what it meant.
It was OK in the end as the rule was revealed soon after, but from now on I'm waiting until something is explicit even if I'm 99% sure what it means.
am 5. April 2025, 07:49 Uhr von yofacey
Q: Feeling the same question as some asked above - can we use the kropki dot immediately, or do we need to wait for its definition?
A: You should wait until the associated rule is revealed.
am 4. April 2025, 22:53 Uhr von Guvenistan
Early on we find a kropki dot, are we allowed to assume we know the rules governing kropkis? If not, perhaps hide it and if so, perhaps add a rule. Either way, a clarification would be appreciated. Thank you!
--- EDIT ---
Going through it further, I can confirm you can NOT use kropki logic until told so.
am 4. April 2025, 14:22 Uhr von SkepticalMario
I would have put it on the puzzle if SudokuPad supported clickable links there, but it does not (for good reason, frankly).
I realize there is a lot to keep track of, and if these comments get too cumbersome, I will create a Google Doc FAQ and link to it in the puzzle description.
am 4. April 2025, 14:19 Uhr von welgen
Ah, in the rules card. There it is. I looked for it in the learned rules section (and everywhere else in the puzzle itself).
am 4. April 2025, 13:56 Uhr von SkepticalMario
The link appears in the rules card in SudokuPad interface, not in the puzzle itself; scroll all the way to the bottom?
am 4. April 2025, 13:53 Uhr von welgen
I double checked three times, I can't find a link anywhere in the puzzle. I have the boss cell selected.
am 4. April 2025, 13:19 Uhr von ndsurgenor
I was confused by the 'boss puzzle' as well. It appears as a link in the regular rules box (not the one in the puzzle) when you are in that relevant section.
About half way through on my first day of solving and loving it!
am 4. April 2025, 13:03 Uhr von welgen
I found the first boss, but can't find the associated boss puzzle. Am I missing something obvious?
Love the idea so far! Luckily this starts easy enough, so I can at least solve parts of it. The 5* parts will be way too hard for me.
am 4. April 2025, 11:40 Uhr von puppyvardy24
holy moly guacamoly i tried it but it is not for me but how mutch time and effort has been put in this puzzle unbelieveble how can we donate to this masterpiece
am 4. April 2025, 04:11 Uhr von SkepticalMario
Added note for Large Puzzle UI