Well,i said i would post screenshots of every race,so i will do so. Heretical 2 images restriction...
If you mean the terrain,no,it has some pretty steep slopes and mountains. Its just that for sake of the screenshots i attempted to find places as flat as i could. But like Mark says,its an old game,dont expect as much terrain detail as for exemple ARMA 2.
I can say one thing: long time ago when the only WH40k games available were Chaos Gate and DoW1 I HAD A DREAM - I wished I could play as a SM or CSM in an open Wh40k world environment shooter that would allow you you to use all the available weapons, vehicles, units with no restriciton. Just to feel like a real Chaos Marine on a real combat mission. When I first saw OFPW1H40kmod I went like oh my god, the dream may come true! And it did, really. No other game (except for Chaos Gate perhaps) gave me this feeling of full immersion in WH40k world. I played hundreds of coop missions with my friends experiencing all possible tactical scenarios. It was a great fun. Later i started making my own single\multi player missions which turned out to be even better than the ones I could find before. Sure there were some technical problems with making all these mods versions work fine together and some things are not well represented in this mod like melee for instance, but still, generally it's worth the trouble. (besides, the fighting in OFP mod is pretty realistic and difficult, you need to really stay sharp all the time and have a well developed tactical sense. i still play it from time to time with my friends via lan, it's a great Wh40k experience and socialising as well .