That's how it used to be... back in pre-alpha and beta stages. They changed it right before development, sadly.
It must be pre-alpha. I started playing in beta stage. Still got the CDs . I guess it would have slowed things down to much, if you think what kind of hardware was 'normal' at that time.
They used different textures in the pre-alpha which the general public does not have access to. The shader was the same, though it looks like they really excentuated lighting.