I get the following error when trying to start the game...

Running SOMA
process 2549: arguments to dbus_connection_open_private() were incorrect, assertion "address != NULL" failed in file dbus-connection.c line 2664.
This is normally a bug in some application using the D-Bus library.
D-Bus not built with -rdynamic so unable to print a backtrace
support/gog_com.shlib: line 94: 2549 Aborted (core dumped) ./"${bin_64}


edit: You need to remove the SDL2 libs and run the ones on your own system for Arch based distros.

Thanks for that. I can confirm it fixes the problem on archlinux 64-bit.

Just rename:

game/lib64/libSDL2-2.0.so.0.4.0

to something like:

game/lib64/libSDL2-2.0.so.0.4.0.bak

and it runs.

.... works!