Click a picture to play its demo. Each package installs from npm as @johnmorrisdotca/<name>, and its README says what its Japanese name means. They are the games and tools of itsutsu.com, taken out so anyone can use them.
Code: its code
Code: Toranpu · Hitotsu · Narabe · Sugoroku · Domino · Jarajara · Gunjin
Code: Tsunagi · Suido · Kazu · Meikyuu · Jirai · Tobiishi · Karakuri · Houseki · Kyuubu
Code: Kotoba · Bushu · Hikidashi · Kumimoji
Code: Chizu · Tenka · Korokoro · Tane
Rules are pure: every move makes a new state and changes nothing it was given, so a game can be saved as text, replayed, and checked on a server. Deals are seeded: the same seed gives the same game in every browser. All of it is MIT licensed.
Also here: SumiLabu, MicroPython firmware and a telemetry dashboard for e-ink clocks.
The pictures are made from the live demos by scripts/ (pnpm cards, pnpm banner), so they can be remade when a demo changes. Lettering is Geist and Zen Old Mincho, both under the SIL Open Font License.