Since I can't submit a technical support request for some reason (what's up with that GOG?) I'm hoping someone else has seen this issue, or can suggest troubleshooting steps. I just downloaded the archive, verified the checksum, unpacked, and ran start.sh. Wasteland comes up, looks great, sets graphics to Beautiful automatically, but I hear no sound. System audio works, changing volume makes the volume change sound. In-game audio settings show game sound should not be muted, but I don't hear the intro movies, or any music or sound effects at the menu. I haven't found any useful logs to submit yet, but I do get a core dump on (seemingly normal) exit, which may or may not be related.

$ ./start.sh
Running Wasteland 2
Set current directory to /mnt/sda13/wasteland2/game
Found path: /mnt/sda13/wasteland2/game/WL2
Mono path[0] = '/mnt/sda13/wasteland2/game/WL2_Data/Managed'
Mono path[1] = '/mnt/sda13/wasteland2/game/WL2_Data/Mono'
Mono config path = '/mnt/sda13/wasteland2/game/WL2_Data/Mono/etc'
*** Error in `./WL2': corrupted double-linked list: 0x0a585908 ***
support/gog_com.shlib: line 199: 14693 Aborted (core dumped) ./"${bin_64}"

Eventually yes. I've been able to get wasteland 2 working in the 32 bit sound system, but not the rest of the system, although never on boot without killing and restarting pulseaudio. Still working through making it all play nice together, but I think the 32 bit libraries mentioned are the solution.

EDIT:
apt-get suggested I install pulseaudio:i386 when installing libasound2:i386, so I did. That turns out to be a mistake, best I can tell two instances of pulseaudio daemon were starting and no sound could play until the second one was killed. Uninstalling pulseaudio:i386 and reinstalling pulseaudio:amd64 worked to resolve the siuation. The above is the whole solution.