Compiled from various notes posted on piazza.

At least in some cases, pygame 1.9.6 has problems on OSX. If you seem to be having mystery bugs with the graphics for the MPs, install pygame 2.0.0.

brew install pkg-config
python3 -m pip install pygame==2.0.0.dev6 --user

This wasn't an issue last year. So whether 1.9.6 works may depend on your version of OSX and/or python. We're not yet sure.