Darvond: And even the current installer isn't perfect, as I found out with Little Inferno requiring some i686 deps. (Resolved, thankfully.) I know that one can use the ldd command in order to check and see what libraries/so files are required. I wonder if GOG can/has implemented such a thing?
(...)
If the game needs extra dependencies we always put that information in the system requirements field of the game, see here for Little Inferno:
https://www.gog.com/game/little_inferno That solution is obviously far from perfection (as we use only names of Ubuntu packages, and it puts a bit of extra effort on the user).
The problem is, Linux is still fresh grounds for many game developers and often they don't know they can satisfy dependencies by putting needed libraries in the game folder or that they should produce a 64 bit binary. And what to do about old games, that were compiled years ago only with 32 bit in mind? Or with game engines that don't offer 64 bit support, such as Game Maker?
And shipping the libraries with the game by GOG might sometimes prove problematic, as it causes compatibility issues (that's why we stopped doing so for some time already).
There are situations where you cannot avoid installing extra dependencies on the user's side. We are actively investigating possible ways of fixing that problem.
RE: AppImages
As many of you noticed, AppImages have their own disadvantages.
I believe they are not suitable for shipping games, at least not in the current shape and surely not for DOSBox or Wine titles, or any other games that require ability to write files in the game folder.
We're gonna stick with installers in the foreseeable future.