Apologies for my having missed 40k references above, but can we agree genestealers probably owe much to Alien, No One Can... and Necrons to Terminator? Though maybe in strange sense Berserker by Saberhagen.
Before current IP wars, re-using rifts in music and ideas in scientific romance, sorry, VSF is showing, SCI-FI, is just what you did
I do remember semi-regular 40k death world events at a local store last millennium were a scream. Right there with 40k deathraces...
Doug