.5 fps huh? Got to love the internet, everyone can make professional claims based on no useful experience. It looks like the TnT2 might not be able to run it due to no current driver support, not HT&L.
I have WinXP. I was using the Voodoo5 5500 PCI with Amigamerlin 3.0XP full. I was playing in multiplayer. I had everything on low and all optimizations on in the drivers. I might not have had the OpenGL dll that they have. Although I have installed it, but because I installed drivers on top of that for an Nvidia card, it might have replaced it. Or I might have deleted it. The claims I made was from my personal experience. The reason why I thought it was working poorly was an educated guess.
Every experience my vary from another. In your link to the 3dfx help page they say this for Hitman 2:
"Notes: Using this method,you will be able to play the game (decent speed even on my Celeron 600), but all characters will be white (due to the 256*256 texture limit). There is no way around this, until a special OpenGL driver that will overcome this limit is released, for now they won't have any textures, but they will be shaded, so it is possible to overlook it. Apart from this, no missing or corrupted textures are present (as far as I can tell). WickedGL works, it will give you a little performance boost and characters will be black, but 2D textures (menus, inventory, etc.) will be seriously corrupted. 3dfx MiniGL won't work at all (hard freeze when running the game), same goes for MesaFX (cannot initialize OpenGL), but there is a good chance that future releases of MesaFX will work and maybe fix more issues."
I have played the game with decent speed and all the characters where fine. There no problems with the graphics. 1024x768. Drivers personally optimized. In-game settings on medium.