I very much hope people link more like this here. My favourite right now is the love solitaire, and jongmah

https://love2d.org/forums/viewtopic.php?t=95641

https://www.jongmah.com/

I had not seen the love solitaire, but I have made a heart-shaped Kakuro puzzle into a book and minimal web app:

https://www.kakurokokoro.com