PICO-8 is a 'fantasy' virtual console emulator, costing 15USD for a personal multi-platform license. In essence it is a cross-platform IDE for creating 1980s-style low-res 8-bit games, including both sound and graphics. The game scripting is done in the Lua programming language. The games can be run either within the PICO-8 IDE itself, or as a web-based game (for non-subscribers) in a modern browser. The web browser needs to be on a desktop machine (e.g. Windows, Mac, Linux inc. Raspberry Pi) using a keyboard and/or USB game controller. The games can be saved in pseudo-cartridges (or 'carts') either in text files or within PNG files.
Main website: https://www.lexaloffle.com/pico-8.php
Resources page: https://www.lexaloffle.com/pico-8.php?page=resources
Wiki site: https://pico-8.fandom.com/wiki/Pico-8_Wikia
Featured carts: https://www.lexaloffle.com/bbs/?cat=7#sub=2&mode=carts&orderby=featured
Quick-fire 7-minute demo: https://www.youtube.com/watch?v=K5RXMuH54iw
And another introductory video (<7 mins): https://www.youtube.com/watch?v=uXveyqOYB5w&feature=emb_logo
Nice 13-minute overview video: https://www.youtube.com/watch?time_continue=303&v=M7azf71z0QE&feature=emb_logo
Cheat sheet: https://imgur.com/iGrP5bK
Enhanced cheat sheet: https://www.lexaloffle.com/bbs/?tid=28207
Online 'Museum of Tweetcart History' (MoTH) - short PICO-8 progs which fit in a tweet: https://museum-of-tweetcart-history.neocities.org/
MagPi: https://magpi.raspberrypi.org/articles/build-retro-game-pico-8-raspberry-pi
Hanselminutes podcast: https://hanselminutes.com/703/tiny-games-with-the-pico-8-fantasy-console-and-joseph-white
Scott Hanselmann bog: https://www.hanselman.com/blog/ThePICO8VirtualFantasyConsoleIsAnIdealizedConstrainedModernDayGameMaker.aspx
PICO-8 tutorial series in MagPi: https://www.lexaloffle.com/bbs/?tid=36930
PICO-8 for Raspberry-Pi starter guide: https://magpi.raspberrypi.org/articles/pico-8-raspberry-pi-starter-guide
Dogfight (currently my favourite!): https://www.lexaloffle.com/bbs/?tid=36919
Snow (3D skier): https://www.lexaloffle.com/bbs/?pid=70497
Pico ski (2D skier - H's favourite): https://www.lexaloffle.com/bbs/?pid=18443#p
Breakout: https://www.lexaloffle.com/bbs/?pid=53977#p
Tube runner: https://www.lexaloffle.com/bbs/?pid=49306#p
I Just Wanna Land! (a flappy bird): https://www.lexaloffle.com/bbs/?pid=56075#p
Tiny Sim Cessna-like flight simulator: https://www.lexaloffle.com/bbs/?pid=20854
The main website for Lua is at: https://www.lua.org/
There is a reference manual for the language at: https://www.lua.org/manual/5.3/
Lua for Python programmers: http://the4thwiki.com/lua/index.html
Learning Lua as a Python developer: https://bugra.github.io/posts/2015/5/9/learning-lua-as-a-Python-developer/
PICO-8 Lua wiki: https://pico-8.fandom.com/wiki/Lua
Lua online interpreter: https://www.lua.org/cgi-bin/demo