I found creating custom cartridge labels to be an exceptionally infuriating process, so I built a python script that can transform any image file to a Pico 8 label. The tool works best with images made especially for Pico 8, with a size of 128x128 and their official color palette, but for shiz and giggles I made it work with any image.

Here's the GitHub repo: https://github.com/amirave/pico-label
If you don't want to go through the troubles of cloning the repo, just save the pico_label.py file inside of it (:

A demonstration of the tool:

This was inspired by u/TimeLoad's URL post, and my compiler is heavily based on his.

We all know how bad Pico8's default editor is, so I made a tool that would (hopefully) help your Pico 8 workflow.

I have the files + a detailed record on URL my GitHub.

Basically, compiler.py takes the .lua files and the assets.p8 from a project folder and compiles them to a cart (final.p8), export.py exports a given project to HTML and JS, and pico8label.py adds a label to a given cart (used in compiler.py).

If you have any feedback or you found any bugs please message me and I'll try my best to fix it!