The current version of Sub Terra Draconis of Crystal Shard
1.6 (74047) seems to be buggy - just showing a black screen
when trying to start it ... maybe due to steam lib dependencies?

The shell output is:
~~
./start.sh
Running Sub Terra Draconis
[S_API] SteamAPI_Init(): SteamAPI_IsSteamRunning() did not locate a running instance of Steam.
dlopen failed trying to load:
~/.steam/sdk64/steamclient.so
with error:
~/.steam/sdk64/steamclient.so: cannot open shared object file: No such file or directory
[S_API] SteamAPI_Init(): Sys_LoadModule failed to load: ~/.steam/sdk64/steamclient.so
X Error of failed request: BadLength (poly request too large or internal Xlib length error)
Major opcode of failed request: 18 (X_ChangeProperty)
Serial number of failed request: 133
Current serial number in output stream: 133
~~
and one has to kill the Draconis process id

I am using KDE neon (based on Ubuntu 22.04 LTS = Jammy) and
tested it also on Mint (also based on Jammy) - so with Ubuntu 22
as recommended OS it should run.

No E-Mai, no discord and only an insecure forum and a game
which just shows a black screen under Linux may not be what
one may expect of game developers.

I will contact GOG support ... but after Linux logo was deleted
from Toy Tanks interest to support Linux users may let a lot
to desire ... but still hoping this can change in future.

The reason is that this game uses the GOG Steam wrapper, mentioned here: docs.gog.com/steam-sdk-wrapper/

Maybe you can use the enable_logs setting mentioned on that page, and see what comes up? I'd expect the wrapper to be compatbile with Ubuntu 22.​​​

I just downloaded the current version for Linux: "1_6_dlc_75705"
and still only a black screen.

It is up to the Devs and GOG to provide an install script so that
the game can start - and on GOG there should not be any
dependencies on Steam.

Normall there are GOG games with error massages about
Steam client etc. missing but fall back to ignore such things.

As I asked for a refund I won't see any new version which may
fixed that bug.

So it would be nice if someone can just play under Linux to give
that info about a new version with number which just run under
Ubuntu 22.04 LTS or 24.04 LTS.