For various graphics issues, here's a resource I haven't seen mentioned yet in the forum:

http://www.zeus-software.com/downloads/nglide
It's a 3Dfx Voodoo Glide wrapper that translates all Glide calls to Direct3D. I've only tested it once, in an end-of-level glitch where after the cutscene I would get a black screen while the game continued the next level (doubly annoying since this was the start of a level where I'm more or less instantly attacked by lions). Although this particular bug is sporadic (I've been able to move through by going back to the save several times), I can report that the first time using this wrapper, I moved right through. (Actually, I'm not even sure if that's a graphics issue or just DOSBox).

Another caveat, my download was (grudgingly) done through Steam, only because I got nine Tomb Raider games in a $10 (or so) bundle.

Anyway, I've had a number of issues with this game, including having to reset my native resolution nearly every time I exit as well as my orientation -- I've wound up with portrait and (flipped) landscape (also known as upside-down). I'm hoping this helps, and I'll re-post with further results, and maybe others will do so as well. Cheers.

Edit: Upon further reading, it appears that, out of the box, this wrapper doesn't work on DOSBox games using Glide; however, instructions are given to make it work with a DOSBox patch.

Edit #2: Well, while doing a search for Zeus/nglide, I stumbled across this GOG general discussion thread:

http://www.gog.com/forum/general/gog_zeus_software_nglide_partnership_announced
So GOG and Zeus are partners. Anyway, TR is listed as a compatible game with this wrapper:

http://www.zeus-software.com/downloads/nglide/compatibility
You just have to do a little tweaking.

Nglide is not that good as dgVoodoo. I does not allow to overrider glide gamma properly, have not that good performance cant render in anything but dx9 while dgVoodoo have range from DX7 (which is the best for compatibility) to DX11 and nglide does not have wrapper for 16 bit dos\win games, does not have 2 many settings.
And you will never ever set proper gamma in TR1, the only way to fix insane brightness is to use dgVoodoo in DX7 mode with "glide gamma" unchecked.

This kind of "partnership" is bad for games and gamers, because now GOG would prefer this inferior wrapper to older superior wrappers.

While I can't dispute the technical issues Voodooman raises (as I've not used dgVoodoo much myself), I can say that nGlide is superior to the default wrapper that comes with the Steam version (and I assume the GOG version) of TR1. nGlide effortlessly allowed me to run the game at 1080p (4:3 pillarboxed) with vsync and much darker gamma than the default wrapper allowed. If you're not shelling out for Glidos I recommend nGlide as a quick and easy enhancement for TR1.

It does. Just launch nGlide 1.00 configurator and set gamma to 0.5. I can understand you like dgVoodoo more, but if you think dgVoodoo is superior to nGlide in terms of compatibility with Glide games, you should really see the doctor.

http://www.zeus-software.com/downloads/nglide/compatibility