I was pleasantly surprised when a friend texted me after work to say this game was on Hacker News. I hope it brought some small joy to your day. Some comments helped identify some minor tweaks. I do not expect to have time or motivation to make bigger changes soon. Feel free to make GitHub issues.
Hello, original author here. I was delightedly surprised to see this game got attention. I believe I referenced https://wcdf.net/rules.htm when writing the game. The game has been updated. If a piece is clicked and has no moves, pieces with moves are briefly highlighted.
I believe I referenced https://wcdf.net/rules.htm for rules. I had these questions myself when writing the game. Updated the README to link to the intended rules.
I thought the same thing. Although it is unsettling to see how copyright infringement is turning into witch hunts this was still probably the funniest thing I've read all day.