It is NOT solved. The main issues are two. One is a crash bug and a "heads don't render well and neither does anything above ground level." This is a Z buffer issue fixed by adding -primary -sortbyz switches to the command line (target field.)
The other is color issues on desktop windowed mode, which requires -32bit added to the switch line.
Next up is the Z buffer response speed which doesn't have a switch, -noflipwait was supposed to do that, but it does't seem to on my machine, and there's no zbuffer depth as -zbufferinfinite doesn't do it either, and neither do they do it together.) The game runs silky smooth with FSAA on max, Supersampling on max, etc. I cannot get it to render the zbuffered stuff like WATER properly, and I cannot get it to render walls BEHIND the character in focus when panning the camera.
The line that fixed most of my stuff except water Z buffer and wall panning slow responding zbuffer cropping is as follows:
"C:\GOG Games\Darkstone\Darkstone.exe" -32bit -full -nointro -primary -ignoreagp -sortbyz -hardmouse -colormouse -tripplebuffer -noflipwait -secondarycache -antialias
I added the other options because they make the game much prettier and smoother than originally, hardware mouse cursor was a BIG deal in the old days. Even if the processor is overloaded, the videocard draws the cursor in hardware. I added -ignoreagp since I wasn't sure that might be causing graphics glitches looking for an AGP switch / card. I just forgot it in there but it works so I left it. (After -primary and -ignoreagp, the crash bug I had vanished.)
All those options forced makes the game look prettier than it ever did on the original desktop (before my original disk walked away, which makes me glad I found it on GOG.) The GOG version does make things more difficult in certain ways. I don't recall progressive casting speeds and other such issues on the original version I had, even patched. This must be a new playability patch by GOG. My lvl 1 mage could cast one missile every other second. At lvl 12 he can almost spam cast. I recall spamming missiles like crazy in the old days. Its an interesting mechanic to add, and probably for the best, mage was OP as hell. (Other than teleporting beasties like the Vampire killing you in one hit because you listened to guides and maxed magic and had 50 hps at lvl 20. Me, I've learned long ago, all point and click games that aren't a single stat spam game, require your hero to have durability, mage or not. Diablo + Mana Shield Mage was the only one where I found extra End/Con/Vit stat to be unnecessary.)
My warrior and thief party, on the other hand took longer to get to 12, but were a LOT of fun. The thief's aggressive AI seems to take pauses here and there. Kind of annoying having to reload because the ol' boy is just sitting there, twiddling his +12% to hit throwing knives and the snakes just mowed my warrior down. So other than the retarded backup AI, the game plays well.
I haven't gotten to Draak yet, but I imagine he'll probably be just as much of a pain as he was in the original days.
I still can't fix those glitches with the camera pan Z buffer slow redraw, and the water being rendered THROUGH/ABOVE ground, and I've tried everything I can think of. What annoys me is the fact that this is something that shouldn't be an issue on NEW VIDEOCARDS!! This is basic Zbuffer issues folks. As another poster wrote somewhere on GOG forums: "I haven't heard of Zbuffer issues since... 1998?"