I had the same problem on my mac, I'm using Big Sur 11.6. I got it starting with JP's instructions at http://vectorpoem.com/playscii/howto_main.html#runfromsource
I did have to use pip3 instead of pip, like this.
pip3 install pysdl2 pyopengl numpy pillow appdirs pdoc
When I ran this code in terminal, the only library that had a problem was the psydl2. Something about a legacy version and building a wheel. Kinda over my head tbh. Running playscii.py tells me it cant find the mixer.
So I had to download the .dmg file from https://github.com/libsdl-org/SDL_mixer/releases and run it to get the SDL2_mixer.framework folder. I moved this folder to my Macintosh HD / Library / Frameworks.
Now playscii tells me it cant find a document named version. This is what I did to get around it, I don't really know why it works
1 Install Visual Studio Code https://code.visualstudio.com/ and its extension for python at https://marketplace.visualstudio.com/items?itemName=ms-python.python for some reason, using terminal with this process didnt get the same result as VSC
2. find the file named "version" in the playscii source folder.
3. rename it to something else, I renamed mine to version_ so I wound't lose it.
4. select the playscii.py, open with > visual studio code 2. It might tell you not to trust the file, so click manage, then trust. click the run and debug button on the left side bar, then the blue run and debug button. Again it says theres an error, at lines 1080 and 1111. You can press the red square at the top to stop the debug mode.
5. I changed the file I renamed "version_" back to its original name "version"
6 run the playscii.py with visual studio code again, and this time it finds the version file and playscii opens!
Sometimes the version issue returns and I'll have to redo steps 3-5 again before playscii will run.
Hopefully this works for someone else with a mac too!