I noticed that the argument I had in mind didn’t work out quite as intended in the previous Maxi Loop, here’s an updated version.
Rules Draw a single closed loop that connects cell centres horizontally and vertically, visiting every cell. Clues indicate the length of the longest loop segment in that room.
Here’s a Maxi Loop puzzle. It probably doesn’t quite deserve to be called “hard” due to the small size, but the intended logic should qualify.
EDIT: This didn’t quite work out intended, see Puzzle 91b instead.
Rules Draw a single closed loop that connects cell centres horizontally and vertically, visiting every cell. Clues indicate the length of the longest loop segment in that room.
Here’s a Horse Snake puzzle.
Rules Shade some cells to form a snake which does not touch itself, not even diagonally. Head and tail are given. Clues indicate the number of shaded cells that are a knight’s step away from the clue. Clues can’t be shaded.
(I’m pretty sure you can drop the “can’t be shaded” part and solve this as a “transparent” Horse Snake.)
Some quick notes on how to get the GP score tables into a useful shape, in order to be able to compute something like the below top 10 by best four results in the first five GPs (using preliminary results for GP 5). So I don’t have to figure this out again next time, and so you can play along at home.
rank | name | points
------+----------------------------+--------
1 | Ken Endo | 3706.7
2 | Ulrich Voigt | 3285.9
3 | Hideaki Jo | 3235.5
4 | Kota Morinishi | 3102.1
5 | Nikola Zivanovic | 3054.5
6 | Robert Vollmert | 2905.2
7 | Will Blatt | 2896.7
8 | Prasanna Seshadri | 2834.7
9 | Yuki Kawabe | 2834.5
10 | Michael Ley | 2806.7
The scripts used to do this are available here.
We’re currently running a review series for the 2016 24 Hours of Budapest on croco-puzzle. I made this Anti-Knight Kakuro, a type which occurred in Tawan‘s set. It turned out to be a bit too hard.
Rules Solve as a standard Kakuro. In addition, equal digits must not be a knight’s step away.
Here’s a Checkered Fillomino, flowery theme.
One more GP round over, with the US round last weekend. While we’re waiting for results, here’s a video recording of my solve. (I’ve been recording the last few, prompted by Endo Ken; GP round 4 where I did relatively terribly is still missing for technical reasons.) No idea where this puts me, but I should definitely work on my Slitherlink solving.
EDIT: fixed video link
One more Tom-tom puzzle. That’s it for the series.
Rules Fill the grid with digits 1-7, so that no digit repeats within a row or a column. (Digits may repeat within rooms.) Clues indicate the result of applying a basic operation (addition, subtraction, multiplication, division) to the digits within that room, starting with the largest digit.
Or see the instruction booklet.
One Tom-tom puzzle.
Rules Fill the grid with digits 1-7, so that no digit repeats within a row or a column. (Digits may repeat within rooms.) Clues indicate the result of applying a basic operation (addition, subtraction, multiplication, division) to the digits within that room, starting with the largest digit.
Or see the instruction booklet.
One more Nanro Signpost.
Rules Shade some cells, so that all shaded cells are connected, and such that shaded cells don’t fill any 2×2 square. Clues indicated the number of shaded cells in an area; each area must have at least one shaded cell. Whenever two shaded cells touch across walls, the number of shaded cells within both areas must be different.
Or see the instruction booklet, with a somewhat different formulation of the rules.
Maybe Puzzles 
