(I found this originally through Authors Publish, issue 446)
Severed Press is an e-book and print on demand publisher that specializes in sf and horror. They are currently accepting novel-length manuscripts in a number of themes and subgenres.
Here's the list of what they are looking for:
Killer sea creatures or monstrous kaiju fiction: Creature features about monsters that come from the deep, or maybe even somewhere more terrifying. Minimum word count 30k.
Dinosaurs : Lost world adventures featuring terrifying creatures from the past. Minimum word count 30k
Military horror/sci-fi: Like Predator or Aliens, a military unit faces off against an unknown threat from beyond the stars or from another dimension. Minimum word count 40k
Apocalyptic or post-apocalyptic scenarios (including TEOTWAWKI or SHTF): Stories that explore the end of the world or life after it: zombie outbreaks, alien invasions or whatever else may serve as a harbinger of the end times! Minimum word count 60k
LitRPG: Stories where characters are transported or trapped within an online game, usually a MMORPG . LitRPG blends traditional science fiction and fantasy with gaming elements and mechanics. Minimum word count 30k.
LitFPS: Stories that blend fiction with First Person Shooters. Minimum word count 30k.