Genre Spotlight 19: Raneko (Puzzles 255 and 256)

Today's puzzle seems to be an somewhat recent Nikoli type, debuting in issue 166.  I'm unable to find any instances of this puzzle online, other than listings on Cross+A and janko.at, and one grid in the GAPP series.  It's a neat type, combining region division with Minesweeper-style clues.  (Though these only count orthogonally adjacent cells rather than diagonally adjacent ones, so maybe they're actually Koburin-style clues?  Shrug.)

Rules. Divide the grid into regions of orthogonally connected cells. Each region must contain exactly one circle. A number in a circle indicates how many cells are in the region the circle belongs to. A black cell is not part of any region, and indicates how many different regions it’s orthogonally adjacent to.

I'm using the Nikoli example grids here, which are lower-quality images but showcase the fact that the genre was originally constructed with cat symbols instead of circles.  Everyone must know this vitally important information.

            

Genre Spotlight 18: Gardens (Puzzles 253 and 254)

It's always surprising to see what niche puzzle types lurk in the depths of the internet.  I found Gardens tucked away in janko.at, attributed to a German puzzle designer named Uwe Wiedemann.  It's a cute type.  It combines Nurikabe with Shikaku to get a puzzle that, while not as expressive as either original genre, still has some interesting interactions.

I've modified the presentation slightly to change it from a "regions" genre to a "shading" genre.

Rules: The diagram contains small gardens, i.e. rectangular green areas separated by hedges (shaded cells). Number clues cannot be shaded, and every garden contains exactly one number equal to its area. Each 2x2 square must have at least one garden square.  Gardens may touch diagonally.

                 

Genre Spotlight 17: Haisu (Puzzles 251 and 252)

As of the time of writing, Haisu is about eight years old and has a dedicated puzz.link interface, but has yet to branch out into the general puzzle contest world (apart from a few appearances in 24HPC).  That's quite surprising!  It's a very natural idea that can lead to fiendishly difficult puzzles, so you'd think puzzle constructors would latch onto it as quickly as possible.  But maybe that difficulty has turned people off.  It certainly did for me at first.

Rules: Draw a non-intersecting path through the centers of all cells, starting from the S (start) and finishing at the G (goal). Each clued cell must be traveled through on the path’s Nth visit to the region the clue lies within, where N is the value of the clue.

         

Genre Spotlight 16: Sea Serpent (Puzzles 249 and 250)

Sea Serpent is one of many snake genres, which can be a sticking point for many solvers.  (It's me, I'm many solvers.)  I don't actually know too much about the history of this type; I was able to find it in a 2003 24HPC round but am not sure if this is actually where the genre originates.  There are definitely aspects of this type which can be annoying, but overall I think it's friendlier than normal Snake.  Sea Serpent doesn't have a "no diagonal adjacency" rule, and it's possible to place clues which behave more locally.

Rules: Shade some cells to form a non-intersecting path which does not touch itself orthogonally. Circles mark the ends of the path. Clues cannot be shaded, and represent the total number of shaded cells that appear in the indicated directions.

(Example taken from WPC 2011.  Here the snake is represented by a path rather than by a group of shaded cells.) 

Genre Spotlight 15: Top Heavy (Puzzles 247 and 248)

I first saw Top Heavy a few years ago in a Puzzle Ramayan contest and thought it was cute.  At the time, I made a TomTom hybrid but never ended up constructing any vanillas.  I still believe that this type is cute -- it reminds me of Fuzuli in several ways -- but constructing one of these is not easy.

Rules: Place numbers from the range given outside the grid into some cells so that each row and column contains each number once. When two numbers touch vertically, the one on top must be larger.

                

Genre Spotlight 14: Mine Shaft (Puzzles 245 and 246)

Mine Shaft was a genre localized on Puzzle Picnic back when the site was still live.  I can't seem to find it anywhere else, though I wouldn't be surprised if it's appeared multiple times and I never realized.  Mine Shaft is really a Snake variant of sorts; IMO "Hydra" would be an appropriate name for it.  I actually think it's superior to Snake in some ways.  While the less-restrictive structure of the solution means you generally need more clues to make puzzles unique, it also allows for more localized progress in areas, and I think there's more you can do with it overall.

Rules: Shade some cells in the grid to form a "mine shaft" -- that is, an orthogonally connected group of cells which contains no loops (not even 2×2s) and does not touch itself diagonally.  Given circles indicate all cells which are adjacent to exactly one other shaded cell.  Numbers above and next to the grid indicate the number of shaded cells in the corresponding row or column.

       

Genre Spotlight 13: Tile City (Puzzles 243 and 244)

I'm capitalizing on this one during its puzz.link implementation honeymoon phase.  (Feel free to deduce the length of my backlog from this information.)

Tile City was introduced by PuzzleSquareJP user _AtomicNeoN_ way back in February 2022.  It seems to have been quickly relegated to obscurity, as there are very few puzzles after the initial batch.  That said, the recent online interface has resulted in a small resurgence of the type.  It's a neat ruleset!  It combines a familiar "no 2x2" rule with interesting logical steps that result in a unique feel.  (In particular, there's a 4-star on PuzzleSquareJP that I tried but couldn't break into....)

Rules: Shade some cells such that each region is either fully shaded or fully unshaded. No 2x2 region may be entirely shaded. Each group of orthogonally connected unshaded regions must contain exactly one region of each size, from a region with only one cell up to the largest region in the group. Regions containing numbers must be unshaded, and the number represents the size of the largest region in its group.

         

Genre Spotlight 12: Minesweeper (Shape Bank) (Puzzles 241 and 242)

This may seem like a new variation from the title, but it's not really that new.  The main focus/inspiration of this post is actually Minesweeper (Pentomino), a somewhat rare but very cool riff on Pentomino placing puzzles.  That said, there's no reason the ruleset has to restrict the puzzle to just pentominos; in theory, any bank of shapes could do, right?

Rules: Place the given shapes into the grid, rotations and reflections allowed. Shapes cannot cover the numbered cells, and different shapes cannot be placed in adjacent cells that share an edge or corner. Numbered cells indicate how many of the surrounding cells (including diagonally adjacent cells) contain parts of the shapes.