I’m not a programmer or game designer by training or background, but I love the PICO-8. It has been around for a number of years and had a bump in awareness in recent years because the game Celeste was originally a PICO-8 game.
PICO-8 is a “Fantasy Console” developed by Lexaloffe. Using unromantic terms, it’s a virtual machine environment that has support on Mac, PC, and Linux clients and programs can be exported to a web environment too. It supports 16 colors in a 128×128 display with 4 channel audio. The executable environment contains a terminal, text editor (with syntax highlighting), a sprite editor, a map editor, a SFX editor, and a music tracker. There are some other limitations but unless you’re a professionally skilled programmer, you probably won’t bump into them.
Now you ready for the “cute” stuff? The program executable are distributed in .PNG format and the code is steganographically embedded in the alpha channels. Here is my first “complete” game I wrote in it:

If you save that file and load it into your PICO-8 environment, you can play my train simulator about driving the MAX Light Rail through Portland. If you want to play it in-browser, here’s the link.
My next game is in development hell, but it’s an endless skater called Zamboni Mayhem. I’m proud of the randomized sprite colors for skin and scarves, and the dynamic music that queues when the Zamboni shows up to run you over. You may have to reload the cart after you finish the game - I don’t remember if it’s returning to the title screen correctly! 😆
I’m probably the most proud of this cart I made that is just a container for music I’ve written for games and projects and just stand-alone tunes. It’s called “music(-1)” which I think is funny because it’s the API command to stop playing all music on all channels.
Best of all, you may already have a PICO-8 license! It was included in the Humble Bundle for Racial Justice! Go dig it up and get writing and playing! The best way to start playing with it is to type “SPLORE” at the prompt. Splore interfaces with the PICO-8 BBS so you have access to pretty much any cart anyone every uploaded for PICO-8. If you save them locally, you will be able to see the code, edit the sprite sheets and maps, play with the audio and learn by doing!
What other micro environments do people use? I know that Game Maker and RPG Maker are popular for all kinds of projects. Lexaloffe also has a voxel-based environment called Voxatron that is very similar to PICO-8 in philosophy.
Anyone else done anything in PICO-8 (or your favorite micro environment) that they are courageous enough to share?