I can confirm that those are available to 64-bit Mint 18.3... just do the following to find them: Open Synaptic, click the "Architecture" button in the lower left corner, then select "All" (or arch: i386) in the panel at the left of the window. Next, use the quick filter to find the package you need.

You can also use the terminal: sudo apt-get install libsdl2-2.0-0:i386 libopenal1:i386 libudev1:i386
should work.

Thank you very much; I'll go and live-run 18.3 again. Much appreciate. :-)

EDIT: have done that, and the game runs perfectly. Back to newbie-land I go, lol, and thank you for taking the time to explain. Mint have done such a good job with this update.

This is a Linux thread and GOG Galaxy hasn't been released for Linux but, if you meant the GOG.com website, then it would be something misbehaving with your browser's session-saving and you should try navigating the tab to somewhere else.

If, by "my library", you mean the listing of games you own, you can only choose to hide things. Like Steam, they assume you paid real money for things and don't let you permanently revoke your own access to what you paid for.

If you actually mean "the set of games that Galaxy has installed on my PC", I can't help you there because I've never used Galaxy.

So, what would be the official way for GOG customers to request a Wine wrapper: "show us your demand for such wrapper"? By and large I don't need them, and certainly not for JJ2, but I'm not aware of how GOG is soliciting requests for this.
Allow me to request a wrapper for Xanadu Next as Judas hasn't bothered to debug the color issue any further.

As I said over at GOL, GOG are welcome to use any of my wrappers as the basis for official/"semi-official" releases... I'll even help with preparing official releases if they want :) Should make things a lot easier as most of the work is already done. They would need to get publisher approval though. Also third party components might pose an issue, but I'm not entirely sure how much of an obstacle that would be as I see other official wrappers have used quite a variety of native components.

Tip: I forget where I in the GOG forums I saw it mentioned that the 64-bit DOSBox is less compatible than 32-bit, but the Free Pascal wiki gives a specific reason why they recommend 32-bit DOSBox:

The FPU emulation in 64-bit DOSBox is inaccurate.

(They don't say whether this problem affects current SVN releases too or whether it's just an artifact of DOSBox not having made a new release in seven years despite development being ongoing the whole time.)

It's also a bit weird they are still using Sourceforge for bug reports. They should have migrated to Gitlab / Github.

well, this is certainly the wrong way to show GOG that there is demand ;)
it just strengthens the impression outlined in the linked post, that people are not exactly eager for wine-wrapped installers. gotta try a different approach :p
And expecting GOG to fix wine for a game that is not working ... ? do you really think that is going to get you anywhere ?

How is it worse than Humble Bundle sponsoring whole Linux ports? Surely doable, if they wanted to.

what? not sure what you are trying to say? i never said Gydion is worse than Humble Bundle?

I mean why is it a worse idea for GOG to fix Wine to release some wrapped game for Linux, than for HB to port whole games like they did (partially) with Shadow Warrior remake? GOG can even go further, and do what HB did by hiring professional Linux developers to port games.

i never said it is bad or worse or anything. Just that requesting it seems pointless
given their statements regarding galaxy & linux I don't really see them spending resources on something like that. They hardly see enough demand to ship wine wrappers for games that are working.
Hurling requests like that at them. as I said, do you really think that is gonna get you anywhere?

(and using the fact that on of their employees is not doing enough debugging in their spare times seems a rather odd argument, unless I just missed the humor in that sentence)

According to their open position they are still interested: http://en.cdprojektred.com/jobs/software-engineer-gog/
But I suspect they have hard time finding people.

The salary they offer for such a position probably is not high enough to make people move to Poland. Would be interesting how much they offer...

From what I've seen in the recent videos, CDPR at least get a lot of developers from outside the country now. But a lot don't feel too happy about the working atmosphere. I hope GOG working environment is better than that.