Too many bugs, including random system resets/reboots.
First, after not playing for awhile, I went to go finish a SP campaign I started a few months ago. After the self-update, it could not seem to find my previous game. I only had two planets left to finish the game, and lost it all. It also did not save/restore my previous settings.
Second, that *forced* auto-update is extremely annoying. For one, it takes several minutes to complete, even when there is nothing to update (I had just prior started the game then exited, trying to force it to save my new settings!) At the very least, give the players an option to not update, and/or not update if any file timestamp is less than a day old. For another, it seems to randomly fail and lock up. I cannot determine when, other than waiting more then five to ten minutes before giving up and terminating the task. (Which I have to go through the whole auto-update process *again* if I try to start it again...)
Third, the game is single-user hostile: I do not play MP, and I do not use Steam or connect to any server for playing. Yet the game wants me to do both. Yes, it lets me close the login dialog, but that is an extra annoyance to do all the time--especially when the other game bugs make needing to restart the whole game repeatedly.
Fourth, the game hard crashed my entire system: The screen suddenly went blank, he BIOS system check began, and my system started it's boot process. This happened three times so far; Once while idle at the campaign screen, and twice in the middle of actively playing.
Fifth, it is not very Linux friendly. Multiple issues here; Depending on settings, it fails to correctly register the mouse position. It locks the mouse to it's window when in windowed mode. It locks up randomly (thankfully, this is rare, but still happens). For me, I installed the portable version launched via mono. And this is another problem within itself--possibly within mono, possible within ZK--in that once I exit the game, I have to CTRL+C or terminate mono via the task manager in order to end mono and return to the command line. And the game does not seem to run very well (if at all) if I try to background the process with an "&" appended to the command line.
My system:
casteele@earth:~$ uname --all
Linux earth 5.4.0-0.bpo.4-amd64 #1 SMP Debian 5.4.19-1~bpo10+1 (2020-03-09) x86_64 GNU/Linux
I have no idea what version of ZK is insalled, as the auto-update seems to do whatever it wants, and right now, I'm too annoyed with it to start i and check the "About" info.