All entrypoints should be running exec $EXEC /opt/factorio/bin/x64/factorio instead of direct exec /opt/factorio/bin/x64/factorio.

This breaks the other entrypoints for arm64 users.

i would suggest putting this bit into a separate script & overwriting the command once and then using that across each entrypoint:

if [[ -f /bin/box64 ]]; then
  # Use an emulator to run on ARM hosts
  # this only gets installed when the target docker platform is linux/arm64
  EXEC="$EXEC /bin/box64"
fi

I can raise a PR to do this