Experiences? Opinions?

3Dfx and OpenGL both appear to work for me, main difference between them being default gamma settings.

3Dfx only goes up to 800x600, but maybe there are other reasons to prefer it over OpenGL? Or maybe one of the Direct3D settings?

I actually went into the game installation folder, subfolder bin, and there is file nglide.
In it I set resolution 1920*1200 with 4:3 aspect ratio (so there is no stretching), 60hz, vertical synchro on, gamma correction 1.0.
In the actual setup of the game launcher, I did not do anything, just run the game.

And the game runs perfectly at 60fps in 1920*1200 with black borders on side (result of 4:3).

So check the nglide config file.

I am pretty sure it runs natively, if it only upscaled the graphics would look much worse.

I believe you are right! Just tried setting the game resolution to 640x480 and nglide to 1600x1200. This makes the menu and loading screens low res / full screen (nice!) but the 3D resolution a crisp and sharp 1600x1200.

Doesn't look better or worse than OpenGL after tweaking the gamma though.

I had a lot of issues with this game before, so much so that I only managed to finish it one year ago. Here's what I can tell about the drivers, if this helps.

The game has had issues with D3D driver for a long time now (from crashes to black letters/waterfalls etc). It was - really - annoying. People actually went for another driver, rOpenGL.

rOpenGL is, as far as I know, a not quite finished driver used before nGlide appearance, but isn't 100% ideal either (control stutter, and fog being too thick and hard to change, apart from a fix which gog.com may have included). But you can finish the game this way, I did and I think it was the most widely used for a long time. It's just that you will probably have to change settings here and there, according to the level.

And finally, nGlide came in, and saved the day! The Voodoo driver came with the last official patch, and with this tool the game is definetely playable, even if a bit blurry (depending on your nGlide settings, which you should tweak a bit indeed). Ah yes, in-game menus are blue, strangely, but it's fine. I literally wanted to play the game again when I discovered nGlide supported Severance, and I launched a new game... It appears to be the safest way to play - playing while understanding too late that fog is too thick, that gamma is too low or high, that your aim with a bow can stutter at the wrong moment... All this, gone with nGlide!

So, I really think you should go for gog's default 3DFx driver/nGlide, not because it's the prettiest driver (D3D was...), but simply because it's the best balance to play the game without adding technical oddities to your (personal) death count, while still enjoying the art and atmosphere.

In any case, thank you gog.com and have fun, it's worth your time!

nGlide doesn't run so fine (at least to me), there are some areas where FPS drops to 24-30 without reason.

With raster OpenGL works fine, the only problem is that you have to force Vsync with Nvidia Control Panel or AMD Catalyst Control Center.

I'm not sure why, but I get much more robust graphics options with OpenGL, which includes all sorts of interesting cel-shading and texture options.

It also seems to be the only one that goes straight to 1980-1020, although I admit I have little knowledge of this.

It is also worth noting the OpenGl is apparently the culprit for the mouse issues some people get (me included).

I am using opengl and it all seems to run great and looks nice, I think anyway, haven't tried out any other options yet.

I am using rOpenGL configured to my native resolution (1440x900), stable with no issues, it seems that the problem with the fog still there, so I patched the game with BODLoader and Fogfix mod (search in ModDB). And that did the trick for me, Orlok and Xathra are playable again, with rOpenGL.

Using rOpenGL here at 1080p, I have been messing with the toon thing and i think made it looks nice.

Cant seem to attach my screenshots for some reason...oh well here are the settings i use.

Edit* seems like it only likes jpg here. There is 1 pic of the settings.

Is there a way to play at 1080p without stretching? Or do you have to play at a lower res?

There are no widescreen resolutions that work without stretching with Severance. I have 16:10 monitor, the game runs at 1920*1200, but I have the picture drawn at 1600*1200 4:3 so I have black borders on side of the screen (better than stretching).
Frankly, game is so good I stop noticing those borders in about 2 minutes when I start playing.

For me OPENGL works perfect at 1680x1050, but it suffers from stretching, so I will search a way to transform it to 16:9 or if not I will choose a 4:3 resolution.

I'm running it with Wine on Linux. OpenGL option works the best.