Ugh! Sorry! Could you try renaming lib/libffi.so.6 to lib/libffi.so.7 and see if the binary bundle works? If so I can upload a fixed build (if that's permitted, not sure.)
The Guix error is confusing because you should be reproducing my exact dev environment. I pushed a commit that disables developer mode in the run-game script. Maybe it will work now? Shot in the dark.
Thanks for trying.