There is an actual Warhammer 40K feature length film called "Damnatus
" made by fans... Unfortunately, Games Workshop killed it
just prior to release. Some crap having to do with copyright law. A real shame since it is very pretty and having read the "Eisenhorn" and "Gaunt's Ghosts" series by Dan Abnett
, I think the filmmakers have captured the feel of that terrifying world.
Here is the trailer
. I hope you know German.