This is really fun, good work Philip!

I haven't seen this puzzle game before, I had to read into it a bit (and had to actually cheat a bit, via solve_puzzles.py.)

Works fine out of the box with python 3, no extra libraries required.

This is good enough to submit to PyPI. Seems like a nice terminal game. Something to play in a tmux pane while tests are running or while waking up with a coffee.

Also I looked at the code, it looks fine.

I saw the multiprocessing in generate_puzzles. Wow. I don't even know what Thread.starmap does. This works nicely.

Keep it up!