Category Archives: Puzzles update: New pzprjs release, and introducing network play

Big new feature on You can now solve puzzles together. Just start network play via “File -> Network play” and share the link. It’s quite experimental and likely flaky, but already so much fun that I decided to share it now.

Otherwise, there’s been countless changes since the last update, which I’ve wrapped up in version 0.13.0. Besides various bugfixes and improvements (see the full Changelog), we have a couple of new puzzle types: Araf, Balance Loop, Doppelblock, Maxi Loop, Mid-loop and Simple Loop.

Puzzle 197: Nurimisaki

Following up the previous Cave, here’s a tougher Nurimisaki. Once you’re comfortable with the type, it might not qualify as “hard” anymore, but if not it will sure feel like it.

That puzzle type switched back to being a shading-first puzzle; I had previously made it an “unshading-first” puzzle for autocheck, but I’ve since changed autocheck for (some / most) shading puzzles to require all cells to be decided before triggering, so the major downside of shading-first is gone.


Puzzle 195: Terra X

Here’s a puzzle from my preparation for WPC 2019 that I don’t believe I’ve posted yet. It’s also sort of a practice puzzle for the upcoming first round of the 2020 Puzzle GP, which features the variant Terra XX.

Rules Place numbers in the empty cells, from the range 0-9. Same numbers can’t be adjacent (but may touch by a corner). Wherever four cells meet at a vertex (marked by a black dot), the sum of the numbers in those cells must be 10.

Puzzle 194: Double Choco

Here’s another Double Choco, probably of similar difficulty to the New Year’s puzzle. I made this one as a “secret solver” present to a user going by the handle “taus” on the Puzzler’s Club chat; the layout is based off their avatar. (There’s a second partial attempt at theming this puzzle that’s a bit less in-your-face.)


Puzzle 193: Double Choco

A puzzle to welcome 2020. This is probably not the first Double Choco puzzle you want to solve.

You can find some easier puzzles in the db.


Rules Dissect the grid into regions. Each region consists of a dark piece and a white piece; these pieces are connected edge-wise, and they must have the same shape, up to rotation and reflection. A piece may contain any number of clues; these give the size of the piece. Christmas update: pzprjs release, and introducing the database

It’s still nowhere near where I want it to be, but I imagine some of my readers are in desperate need of puzzles over the holidays. So I decided to finally announce the database – see below. But first:

robx/pzprjs v0.12.0

It’s been a while since I made a proper release for my fork of the pzprjs puzzle applet. Since releasing v0.11.1 back in April 2019, some of the notable changes have been:

  • add 9 new puzzle types: Aquarium, Castle Wall, Compass, Curve Data, Double Choco, Geradeweg, Heteromino, Pencils and Regional Yajilin
  • there’s now a page listing the rules for a type by example of possible errors, e.g. for Double Choco
  • a variety of improvements to individual types, e.g.:
    • Country Road now has a variant rule to permit empty rooms
    • for puzzles like Heyawake, you can now shade-blank across shaded cells (with mouse)
    • Star Battle now allows placing auxiliary dots (e.g., to mark when a star is in one of two cells)
    • Kakuro now supports blank clues
    • for moving puzzles like Herugolf and Satogaeri, movement is restricted to straight lines

Check the Changelog for the full list. Thanks to all contributors, particularly to Lennard Sprong!

At, you can find an index of publicly shared puzzles from all over the internet. In its present form, it started out as a tool for me to keep up with the flood of excellent puzzles shared on twitter. It aggregates puzzle links (to and from twitter and several puzzle blogs, and lets you track which ones you’ve solved, as well as providing some ways to filter (e.g. by puzzle type or author).

If you miss or, this might help fill the gap. Let me know what you think! I hope it doesn’t fall over from the mass of new users.