I am trying to edit the gamma settings for the 3DFX version of Mechwarrior 2, but whatever setting either in the control panel for the drivers or in a batch file with set sst_gamma does not work. I can see the 3DFX logo react to the changes, but the game itself does not in 800x600. In 640x480 it works as it is supposed to with the game reacting to the corresponding gamma setting. I've also tried with a Voodoo2 card, but it is the same there. Is there some kind of built in gamma control for Mechwarrior 2? Is there any other way to fix this?

Hardware: Orchid Righteous Voodoo 1 4MB
Windows 98 SE
PIII-S 1ghz
Asus P3B-F