Apparently, the 16 bits settings mess with the appearance of the particles. If you make sure that the resolution is not in 16 bits, it fixes any problem with the 'particle clouds'. Does anyone know why is this happening?

Particles require 32-bit color... or at least that would seem to be the most likely answer.

For me, the bigger question is why are you even trying to use 16-bit color, followed closely by why does the game still offer that as an option (its not that old)?

The problem is that 16-bit color is the only option you can choose for higher resolutions :/ (widescreen resolutions too) And with 16-bit color everything in the game looks crappy and ugly.

Not on mine (copy from GOG.com). I have a full range of available resolutions, both in 32-bit and 16-bit. The drop-down list in the game launcher starts with 32-bit color resolutions starting at 640X480 all the way up through 1680X1050 each in 60, 72 and 75Hz frequencies, followed by the same selection of resolutions with "(16 bit)" appended on to it.

Perfect, after uninstalled and reinstalled Demon Stone now i have the choice of 32-bit resolutions in the drop-down list, too. I do not know why I could not select them first, but now it works perfectly ^ ^

I have no 32-bit resolution on win7 64... I will try to reinstall

EDIT: nothing changed, but i found a BAD thing...

Every time I SELECT my video adapter ALL THE RESOLUTIONS ARE DOUBLED !!

EDIT 2: started as administrator...now I can see all the resolutions