I made a single ricchi mahjong game with ai.
https://single-mahjong.github.io
I know Mahjong is a game with a high barrier to entry, so it's hard to attract new players.
I found it difficult to find a single-player Mahjong game that you can learn on your own without friends. (I've only seen one game featuring Kemono-style riichi mahjong)
It explains ricchi mahjong rules and allows you to learn by solving simple quizzes.
It's designed so you can resume playing anytime even if you turn the game off and on again.
I made this game with ai, I thought it would be great to have a game that is as newbie-friendly as possible.
It guides you through the tutorial and helps you decide which moves to make during gameplay, and it also explains how to calculate scores. The difficulty is adjusted, so the guidance is limited on higher difficulties (think of it as the "practical" version).
It supports desktop and mobile (portrait/landscape) both, more optimized for desktop.
I'm working on advanced the game with humble mind to accept some better ideas from anyone.