I downloaded and installed the current version of the game, but I cannot run it. Every time I execute the start script, a themed error message window appears, saying that: "Failed to open descriptor file '../../../Ruiner/Ruiner.uproject", then it exits with error code 1.

I am running Debian Buster. Is this a known issue, or can I do something to help debug this?

Is the game installed or just unpacked? Is there a file game/Ruiner/Content/Paks/Ruiner-LinuxNoEditor.pak and what size is it?

For anyone else running into this issue, if you've manually unzipped the installer, you also need to join a couple of split files (that the installer normally takes care of) by cd-ing to <target_dir>/game/Ruiner/Content/Paks and running: You can also remove the no longer needed split files by running:

Thank you guys, that solved the problem indeed.