When running the game on Linux (not sure if the same issues happen on Windows too), I had performances issues right from the menu: crackling sound, lag in mouse movements...

I tweaked the DOSBox config file (dosboxSWARS.conf, in the game installation folder) and changed output from "OpenGL" to "overlay" or "surface". The game runs fine with that.

Not sure why GOG's config file is set to OpenGL by default? Is that because it's a 3D game and it's supposed to work better than software rendering, at least on older hardware? Looks like it's not really needed for current PCs. Or maybe DOSBox's OpenGL renderer is a bit buggy (at least on Linux)?

EDIT: note that I tried the game in windowed mode only. OpenGL may be needed/better for fullscreen.

Came here to sort out this issue and while it took a bit to find the correct option to change when I opened the file in notepad (wasnt sure what program to use), it 100% solved the issue. Just wanted to say thanks for posting the fix!

If you have AMD/Ati videocard its best to use overlay/surface/ddraw in my experience, if you want to avoid all sort of glitches better not use OpenGL/OpenGLnb.
Note that surface doesn't support scalers and only supports original resolution, so it is not the best choice for fullscreen, ddraw uses some sort of filter just like OpenGL billinear filter, so may not be for everyones taste.

Here is an interesting post on Dosbox's outputs.

I ran into the crackling sound issue a few times but just restarting the game seemed to fix it so I never bothered to change settings. This was in Windows though I briefly tried the game in linux dosbox also, worked fine.