Played the full game for a bit over an hour last night and racked up 566 kills - this is 40K
i love that there is an achievement for killing 40,000 enemies.
you don't notice the slightly sub par level detail and, somehow, i've found myself looking at some terrain pieces and going "wow, that's awesome" - they've lovingly recreated much of the terrain set pieces as seen in White Dwarf magazine. Even the dead imperial guardsmen are scattered about in poses lifted directly from the minatures line
Oh one other cool thing. Getting into the game is super fast, and after that you never see a loadscreen. So either it has a map as big as GTA, or they handle level transitions *really* well. (there are cutscenes so they probably load during these, but you're never left waiting for the game to finish reticulating its splines or some such)