Sorry for the delay. I don't get notifications so I can't know when you write here.
As regarding the error, those 2 files should definitely be there. Something is off.
Any chance you can verify in the game files that you have them in Zoria Install Location/Zoria AoS_Data/Plugins/
There should be 2 files: libsqlite3.so and libsteam_api.so

I will check again that they are there uploaded but others have been able to launch the game so not really sure what's happening.
I will be back with a confirmation.

Both files are there.

The prolog is a completely different piece of software from the current release version (which I guess is what you are looking for - please clarify)? They have different pages on the GOG store front and different pages in your "Games" list.

I think what you are running into is how GoG Galaxy does things.

In GoG Galaxy you need to click on the diamonds to the left of Overview and select "Zoria: Age of Shattering" from the list.

NOTE: When looking from the website at your games you will see two different Zoria (Prologue and "Age of Shattering").

I just thought of another problem you might be having: are you a Zoria Kickstarter backer? If so, you need to go to Backerkit and activate your GOG key there before you will see the release version in your GOG library.