The following parameters can be 'played with' to optimize performance / quality.
Display frames/sec
Shows a FPS value in top left corner
Limit Vertical Sync Rate
Enabling this feature just sets the maximum rendering speed to match the monitor refresh rate. Default is OFF.
Specular Lighting
Enabling this feature gives a specular effect to appropriately shaded objects. Some cards slow down with this setting.
3D Filtering
This is how 3D objects are 'smoothed'. Several options are available, but Trilinear (Default) or Anisotropic (a little better - not all cards support) seems to look the best in most cases.
2D Filtering
Same as 3D filtering but specifically applies to text and textures. Again Trilinear is a good choice. Other choices can look better in some cases, but can also affect frame rates depending on the graphics card.
Antialiasing
Not supported by all cards and can have funny effects if it is turned on through the Windows desktop. Antialiasing tries to eliminate jaggy lines on diagonals by interpolating. (Default-OFF)
Set Depth Buffer
The method used to determine if a face is rendered or not. Zbuffer is the default but Wbuffer. Some cards don't support Wbuffer so try it to find out.
Land Detail Texture Mode
This effects how the detail texture is overlayed on the main texture. Modulate2X is default but experiment!
Texture Mode
This effects how the textures are computed. Compressed saves video memory and is a good choice for cards 64mb or less. 16bit is the default and 32 bit is for very good for cards with lots of video memory.