Under Linux (OpenSuse Leap 15.2 - I realise that isn't officially supported), the game crashes after the initial splash screens. The menu screen with new game/load game/credits/exit comes up, but the game crashes when the mouse is clicked anywhere on this screen.

Out put is:
support/gog_com.shlib: line 94: 20971 Segmentation fault (core dumped) ./"${bin_64}"

This doesn't seem to be a 32/64 bit issue, it doesn't seem to be a bundled/native SDL issue, deleting the acsetup.cfg file doesn't help and not does editing it. There is no clue in the AGS engine output when run from the command line.

The menu screen will still with its animation and sound running indefinitely until the mouse is clicked.

Anyone have any suggestions?

Yes, I had trouble with GOG support using Ubuntu (STS is not really supported - only version on product pages;
but I have the LTS releases and even then ...) - so the 3rd word will end any support request for sure (after my
experience at least - I was confirmed my request were sent/forwarded to Linux/packaging team - but I never heard
anything ...).
I may not be more helpful as I am also not using OpenSuSE ... but as it may be a library problem (as Leap 15.2
was released on 02. July 2020 - and not derived from Debian like Ubuntu and Mint), there is a chance that
the latest AGS version may help with your problem.
I put this description to keyboard problems and was astonished that people seriously advice to get a wrong keyboard
layout ... strange way of thinking when an OSE release is available ...
I just swapped the engine (which was adviced by gamers in that forum several times - but extremely short):
1) Download new AGS engine (here for Linux - other OSs are also available):
    https://github.com/adventuregamestudio/ags/releases/latest # 3.5.0.30 16.02.2021 now
    getting ags_3.5.0.30_linux.tar.gz # or later versions, of cause ;)
2) This file will use subdirectory 'data' as game path and base being GOG install path with script startgame.
    So one can make 'game' being 'date' via 'ln -s game data' in GOG install path and then
    extract the tar archive there - maybe before moving existing files away and linking
    to used names like:
mv game data     # current AGS has game engine in 'data', not 'game'
ln -s data game
cd game
mv Resonance.bin.x86 ORIG_Resonance.bin.x86_ORIG
mv Resonance.bin.x86_64 ORIG_Resonance.bin.x86_64_ORIG
mv lib ORIG_lib_ORIG
mv lib64 ORIG_lib64_ORIG
ln -s ags64 Resonance.bin.x86_64
ln -s ags32 Resonance.bin.x86
ln -s lib32 lib
cd ..
mv start.sh ORIG_start.sh_ORIG
ln -s startgame start.sh
tar xvfz <PATH_TO_DOWNLOADED_AGS_ENGINE>/ags_3.5.0.30_linux.tar.gz
    which should do the job (instead of CLI you can use the mouse if so inclined :).
    For a later refresh of the AGS engine only the last step
    (tar-extraction in install dir) is necessary - so quite easy and fast).
3) Enjoy the new engine - you can use the keyboard layout of the system as you want it and it should work
    (tested for German - on file save); did not work with the original AGS but without problem
    with the new engine - and maybe it is more compatible to later HW (the original one worked
    for me under Kubuntu 20.10 `Groovy' - except keyboard layout, of cause ;).
    One small negative thing is a 2s pause of sound when using KDE volume control changes ...
    but in game changes of volume are working without that gap with the new engine.
And yes, I asked GOG about changing the engine ... so everybody will just use GOG installer and it works like a charm.
But it seems they leave everything to gamers or developers - don't get any answer on my support ticket ...
Thus if having trouble with AGS engines one may look here (it is open source now - so a real OSE being maintained):
    https://www.adventuregamestudio.co.uk/forums/ !
So especially with non-Debian derivatives they may be more helpful in case the latest AGS engine does not run.
    => We are not alone ... even though this impression may be generated from time to time! ;)