Just a FYI for anyone who buys this game on GoG, as of version 1.1.5 (58570), The standalone installer must be missing files. It will install fine, even passes the integrity check, but will not get past the prologue. It will get stuck at an infinite loading screen when you finish the prologue chapter. The fix was to load up GoG Galaxy and have it repair the installation. Once that happened the game worked fine.

For Steam Deck users, the same applies, I had to re-transfer the GoG Galaxy fixed directory to get it to get past the infinite loading screen after the prologue.

Yup. Experiencing the same thing. This sucks because I really would rather not have to install yet another storefront's client/platform

Just to follow up. I did some further checking, and it looks as if no files are missing but many of the files are different. I have been in contact with support, but so far nothing to report. Hopefully they'll fix it soon.

Just as an FYI, there are 140 files that are different. Same file name different file sizes and crc32 hash values. For example the level0 file is 457504 bytes large on the stand alone, but on the galaxy downloaded one that works it is 457648 bytes. The .exe though for both are exact matches for hash value and file size so that implies the same version, while the level0 data are different so that probably explains the black infinite load screen (trying to load data that doesn't exist in the level0 data file in the 144 byte missing data). Most likely the different files are from a different build of the game. Personally I think they built the 1.1.5 stand alone installer and mixed in the files from the previous version of the game in error.

Unfortunately if you don't want to install the GoG Galaxy client, you'll have to wait for GoG to fix it and make a new stand alone installer. They seem to be busy at the moment trying to fix their website so that updates will show up again in your account games list.

Save games stopped loading for me after Gog Galaxy updated the game to 1.1.15, and I had to downgrade it to 1.1.14

Repairing the installation didn't fix the issue in my case

I thought with the Standalone Offline Installers downloaded from the browser you could install v1.0, and then patch it up and stop at 1.1.14 instead