I encountered the same errors on ArchLinux. python 3.8.5, pygame 1.9.6. I think those are just warnings (though legit, I do think you want == and not is).
There was an actual error that prevented the game from launching though:
AttributeError: module 'pygame.sprite' has no attribute 'Sprite'
I noticed that requirements.txt doesn’t pin to a specific version of pygame, maybe that’s the issue?
Also FWIW the jam page tells you to source venv/bin/activate, which isn’t included in the download (but does appear to be commited to your repo).