Puzzle #25 - The Sky's the Limit (Celestial Road)

For the 25th puzzle milestone on my blog, here's my entry for Puzzler's Club Logic Showcase #3, which required combining 2 loop genres to make a new one. Naturally, I mashed up Moon or Sun and Country Road to devise Celestial Road. This puzzle placed 6th of 10 in a very strong field and I'm very pleased with how it turned out. I actually constructed this puzzle before any of puzzles #20-#24, and decided to build easier puzzles of the types to ease into this one.

puzz.link interface   penpa interface

This is easily the hardest puzzle on the blog thus far. Most regions are sparsely clued, but there's just enough information to force one singular path between the symbol alternation and unused cell adjacency rules. If I had to give it a difficulty rating, probably 7 or 8 out of 10.

Next post will probably be a compilation of all puzzles posted so far, with solutions and possibly walkthroughs. Depends on if I can figure out how to make a good pdf.

Puzzle #24 - An Intentional Variant (Celestial Road)

This is a Celestial Road puzzle. Celestial Road is an original mashup of Moon or Sun and Country Road. Draw a loop through cell centers that enters all regions. In each region, either visit all suns and no moons or all moons and no suns in that region. The loop must alternate passing through all moons in a region, and all suns in a region. Additionally, unused cells may not be adjacent across a region boundary.

This is the only solution to the above Celestial Road puzzle. Each of the 2 regions with only suns must be "sun" regions, as entering them requires entering a sun, and all of an entered symbol must be visited by the loop. After a "sun" region, the next region must be a "moon" region, and so the bottom left must use those cells. That renders row 2, column 2 and row 3, column 3 as unused cells. By the Country Road logic, that makes row 2, column 3 a cell that must be used by the loop, which gives the rest of the solution.

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original, broken version

Puzzle #23 - An Accidental Variant (Moon or Sun)

Here is a Moon or Sun puzzle. However, the solving interface will not mark this as correct, as it requires at least one symbol be passed when traveling through a region. I didn't realize this when constructing a later puzzle, so the "variant" rule of "all symbols of a type can be 0" applies here.

This, then, would be a valid solution to the Nikoli example puzzle, as it travels through all moons in the top left, then all suns, then all 0 moons in the top right, all 0 suns in the middle, all moons, and then all suns on the bottom.

puzz.link interface   penpa interface

If the only error you get is "A line passes neither the marks of the moon nor the sun." and you travel through every sun in every other region, you found the solution. Constructing this one was quite the task!
And now, a year later, there's a penpa interface that has a correct answer check!

Puzzle #22 - Into the Sky (Moon or Sun)

Yet again, another new type for the blog. Moon or Sun is a relatively rare type that usually isn't very difficult, but I find them quite fun to both make and solve. The binary nature of each region is interesting to try to think around.

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Puzzle #21 - Across the (Country) Road

Here is another Country Road puzzle. Remember that all regions must be visited exactly once.

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Both sides of this puzzle should be good practice at the two main types of deduction I've learned in the type.

Puzzle #20 - Framed (Country Road)

I have a funny story before posting today's puzzle. Country Road was a genre that I did not understand how to make any progress in the first few times I saw it. The rule about unused cells not being adjacent, but only if across region boundaries threw me off. I don't recall why I took another look at a Country Road puzzle, but it started clicking and that very same rule has some very interesting consequences. Constructing the type, however, is quite the challenge, with managing loop logic, numbers, and region shapes. At least local type fixes are possible!
There is a common variant of Country Road where not all regions must be visited. As the solving interface does require all regions to be visited, I'll treat any puzzles I post with that rule as... a variant puzzle.

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This puzzle may seem inscrutable, but there are actually some very strong constraints and the puzzle isn't actually as hard as it looks.

Puzzle #19 - Vanilla Level (Sudoku)

Here is a Sudoku puzzle in the form of a Chip's Challenge 2 level.

...

Wait, that's not usable?

Regardless, it's an actual level I made and there are other items that need to be placed so that ghosts have specifically laid out inventories so that they press all the buttons to open the door to the exit. Why? Because I was pretty sure I could and without the excuse, I probably would have taken much longer to get to making a Sudoku, as I'm not really a fan of the type.

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Very easy puzzle, though it almost had to be given the reason for creation and the given layout.

Puzzles #17 & #18 - Prime Time (Kurotto, Fillomino)

The two puzzles in this post were constructed for entry in Puzzler's Club Logic Showcase #2, which required a puzzle with only number clues, and only the numbers 2, 3, 5 and 7 were allowed. Each of those numbers had to appear at least once. First I tried to make a Kurotto puzzle, but this was enied due to the empty circles. I'm not the biggest fan of how I made it unique but I like the theme.

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After it was denied, I constructed a Fillomino puzzle, which placed third. Solving it shouldn't be too hard, but demonstrating that it's unique is much more interesting and it uses some novel deductions rarely seen in the type.

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I'm up to 24 puzzles for the blog, with 2 more planned to build up to puzzle 25. I think I'll try to make every 25th puzzle a bigger or more involved one. As always, enjoy :)

Puzzle #16 - Yajilin 201

My goal with this Yajilin puzzle was to showcase a few less common but still very useful deductions in the genre. I urge you to not guess or bifurcate through this puzzle and instead make sure you deduce every step- I promise you'll learn from it.

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If you're really stuck in the last corner, then bifurcating is reasonable. But everything until then is fairly common in the genre.

Puzzle # 15 - Chain (Yajilin)

This Yajilin was built as part of a Yajilin chain, where the black cells from one puzzle become the walls for the next. This layout was quite interesting and lent itself to a very cool deduction in one place.

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Getting a little harder with these. The next post will be another Yajilin and it's definitely a tricky one.

Puzzles #13 & #14 - Simple? Loop (Yajilin)

Here are two more Yajilin puzzles with the same theme.

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Teehee. Both easy.

Puzzle #12 - Hybrid Theory (Yajilin)

Despite the title, the puzzle in this post is actually a standard genre. Yajliin is primarily a loop puzzle where some cells get shaded, and alongside Fillomino is one of the most versatile logic puzzle genres out there.

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Hopefully not too hard- the wall structure itself gives away a lot more information than it first appears, though not much of that information is strictly necessary in a solve.

Puzzle #11 - Simple Sashigane

Sashigane is one of the genres I have the most fun solving, alongside Fillomino, Yajilin, and pretty much any shading puzzle.

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Nothing too hard with this puzzle- probably a good introduction, as it showcases some of the useful techniques for solving Sashigane. And constructing it helped me with some general puzzle construction, too. I hope to include some more complicated puzzles soon, but for now let's round out some introductions, alright?

Puzzles #8, #9 and #10 - Adaptations (LITS, Akari, Cave)

All three of the puzzles in this post are on the smaller side, and were constructed for inclusion in the same Chip's Challenge 2 level as the 125436 Nurikabe a few posts ago.

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First up is a LITS puzzle. The start is fairly obvious, but there's a step following that takes a bit of thinking.

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Next up is the first object placement puzzle on the blog, an Akari. The type usually isn't too difficult without leaning on one of a few deductions, which will hopefully be showcased later.

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Corral (or Cave, or Bag) is a genre that no one can seem to agree on the name or style of. I prefer to think of it as a shading puzzle, though some would treat it as a loop drawing puzzle. In any case, this is probably the trickiest of the batch here though entirely because the rules are trickier to grasp.

Update: the Akari lost a 0 somehow, as pointed out by bmcfluff. This has been corrected.

Puzzle #7 - The Four Fours (Nurikabe)

This Nurikabe is the puzzle that got me making puzzles. See, years ago I had tried making a puzzle with this exact central theme, but completely failed and couldn't force a unique solution. Then I tried again, almost on a whim, and not only could force a unique solution but also keep tweaking to create what I think is one of my best puzzles. I hope you agree!

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Another medium difficulty puzzle, this one harder than the last.

Puzzle #6 - Antisymmetry (Nurikabe)

Anti-symmetry is a puzzle theme where clues are placed symmetrically, but opposite placements are... opposite. For a Nurikabe that means that opposite givens sum to the same number, in this case 8. This puzzle was designed for a logic showcase, and placed tied last :(

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Even though it placed last, people still liked it. Just not as much as other ones entered. Definitely a medium difficulty puzzle.

Puzzles #4 & #5 - Two Nurikabes

The pacee of posting puzzles will slow down a lot once I get through the ones I've already built. For now, I have one more Fivecells that will have to wait a couple months, so instead have two simple Nurikabe puzzles. I used to be really, really bad at the type but I've gotten much better.

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The first of these was built for inclusion in a counting thread on a completely unrelated forum, mostly as a joke. The second was was built for adaptation and inclusion in a Chip's Challenge 2 level.

Puzzle #3 - Introduction to Fivecells

I completely forgot that I made a 5x5 Fivecells to post as an introduction to the genre until now!

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This should be a fairly easy puzzle, though hopefully not trivial. 2/10?

Puzzle #2 - ????Cells

I made this puzzle while on breaks at work one day. Divide the grid into regions such that each number has that many lines drawn next to it. Also, there should be a region of each size from 1-8 cells. Standard rules, for reference.

puzz.link interface   penpa interface

There's some tricky logic to figure out here. Probably a 5/10 difficulty, mostly due to the size.

Puzzle #1 - Fivecelled Donut

Welcome non-existent readers! Today I've decided to make a blog to post the logic puzzles I've constructed, and what better place to start then a FiveCells puzzle that I've posted on Twitter before?

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Probably about a 3/10 or 4/10 difficulty puzzle.