PICO–8って何? - PICO–8ゲーム開発入門(1) | AUTOMATON(by Ryosuke Mihara)
https://automaton-media.com/devlog/technical/pico-8-for-beginners-vol1/
PICO-8 API 早見表、マニュアル日本語版(by Takashi Kitao)
https://github.com/kitao/pico8-api-jp
入門書 PICO-8 ZINE 日本語版(Edited by Arnaud Debock)
https://sectordub.itch.io/pico-8-fanzine-1-japanese
PICO-8 Resources(English)
https://lexaloffle.com/pico-8.php?page=resources