The asset files in total are over 2GB. Because of that, they're both too large to store directly in git and too large to store in github's LFS system, so to get around this
we've had to store the assets files separately outside of the repository ourselves.
You can find the missing files here: https://mega.nz/folder/YCxlRQrS#oG0AbrFDNNLRFjdRVOOv7Q
When checking out the repo, simply create an assets folder and download the contents from that mega link and place them inside.