Dynamic Nebula (Dynamic FoW, Spiral Galaxies)
(Published on 4. April 2025, 15:21 by gdc)
I found an unsuaual way to use the SudokuPad killer cage calculator and decided to make a puzzle to showcase that. This puzzle enables the killer calculator as soon as you have enough fog uncovered to "prove" that you know the size (and total) of the cages (a.k.a galaxies). Thanks to the CtC-fan-discord for testing. Hope you enjoy!
Normal sudoku rules apply.
Fog covers the grid. Placing a logically deduced digit in a cell lifts fog from that cell and possibly other cells.
Spiral Galaxies: Divide the grid into orthogonally connected and 180° rotationally symmetric "galaxies" so each cell is part of exactly one galaxy.
Squares: Digits don't repeat in a galaxy and sum to the value on its central square clue. All centers are marked.
Circled digits count the number of cells in their galaxy.
Example Puzzle
This example puzzle is linked in the rulesbox of the main puzzle and uses the same rules. Each galaxy retains its shape when rotated around its center (orange square) and acts as a killer cage. You can play the example here.
Solution code: Row 9, left to right
Comments
on 28. June 2025, 04:38 by Agent
Very nice!
on 9. April 2025, 14:44 by cbossut
Loved the last 3 rows !
on 9. April 2025, 09:00 by ninjamunk
Spent 95 min on this!
Felt so stupid, but at the end I spotted an error I had made in the beginning, that somehow didnt matter until the end.
Very nice puzzle! I love galaxies.
on 9. April 2025, 05:12 by Cyndatu
this is the fastest i've ever completed a sudoku of this difficulty or higher, i can feel myself improving, amazing puzzle!
on 8. April 2025, 01:10 by Jackler
Weirdly, the hardest part is like the last 3rd. Quick puzzle, under 20min solve, so nice little evening entertainment.
on 7. April 2025, 21:48 by PancakePie
Beautiful! Took a bit of finagling the possible shapes in my mind, but this has opened a new realm of thought in a really fun way!
on 7. April 2025, 09:20 by wuc
Very clever construction. Smooth path. As often on DFog you show where the solve path navigates through. Still tricky at times, the whole puzzle was geat fun to solve thx.
on 7. April 2025, 04:30 by Cascon
Loved this puzzle! very logical :)
on 7. April 2025, 00:42 by v8nagrom
I really got stuck somewhere in the middle of solving this gem because I didn't get the point that every cell in the grid MUST belong to a galaxy. I read the ruleset thoroughly a few times and finally I understand this constraint.
Anyway.
A gdc puzzle is always a pleasure.
Thanks
on 6. April 2025, 22:10 by firespire
Math/Maths is my weak point so I would have passed this if you hadn't included the magic words - Killer cage calculator.
Thanks for taking the the time to include that (probably not easy) plus making an example puzzle so I knew I was up for the challenge.
Congratulations on your CTC feature.
on 5. April 2025, 14:07 by Franjo
Great puzzle! I really enjoyed the whole ride from the top to the code row. Thank you very much for creating and sharing this gem.
on 5. April 2025, 13:46 by dmgciubotaru
This new mechanic is a really nice addition to FoW, channeling your focus on usable hints
on 5. April 2025, 09:30 by TheNineElements
Solve Time: 36:39
I rated this 3/5 difficulty
Excellent puzzle! It's always a treat to solve a @gdc dFoW puzzle, and this was no exception. I really enjoyed the break-in and the logic following several of the dynamic reveals!
I'm not particularly "proficient"/good at spiral galaxy puzzles (I don't solve them often), but I found this puzzle and its spiral logic fairly approachable and straightforward. I felt like the difficulty was fairly consistent throughout the entire puzzle, although I did get stuck for a several minutes at the beginning - forgetting that spiral galaxies couldn't contain repeated digits. Additionally, I also didn't realize that every center square was given - but again this is also just a matter of me failing to thoroughly read the rules (and, in hindsight, it seems very obvious that this should be the case). Once I realized these oversights, I immediately was able to place a digit and reveal a new section - and the remainder of my solve was very smooth and enjoyable after that.
I think this puzzle was on the easier side of 3* difficulty, though a harder 2* rating would also be reasonable IMO. Ultimately I decided on 3* overall due to my longer solve time - though I'm not sure if this was a result of my unfamiliarity with the ruleset rather than the actual logic being hard/complex. Either way, I definitely think an intermediate solver should be able to approach this puzzle without too much trouble.
Overall, this puzzle & its solve path were very enjoyable and fun - and definitely worth solving! Thanks for sharing!
on 5. April 2025, 08:00 by Titus Adduxas
I had to rewind a bit at the end when my logic went a bit awry but it was a very enjoyable puzzle nonetheless.
on 4. April 2025, 23:21 by Tank
Very good puzzle, enjoyed solving it. Got stuck towards the end but found the correct logic and was able to push through
on 4. April 2025, 21:36 by ofsmul
I had a bit of a rough start when I briefly forgot a galaxy could have a size of 1, but after that a smooth (albeit not easy!) solve. Fun puzzle, thanks!
on 4. April 2025, 19:35 by tubahat
luv it!
on 4. April 2025, 16:28 by matiasv5
Really enjoyed it, thanks!
