Aliens: Phalanx is a novel written by Scott Sigler. It was first published in 2020.
Description[]
It's Medieval carnage meets Alien as a pre-industrial society fights against extinction brought about by a massive infestation of Xenomorphs.
Ataegina was an isolated world of medieval castles, varied cultures, and conquests, vibrant until the demons rose and spread relentless destruction. Swarms of lethal creatures with black husks, murderous claws, barbed tails and dreaded "tooth-tongues" raged through the lowlands, killing ninety percent of the planet's population. Terrified survivors fled to hidden mountain keeps where they eke out a meager existence. When a trio of young warriors discovers a new weapon, they see a chance to end this curse. To save humanity, the trio must fight their way to the tunnels of Black Smoke Mountain--the lair of the mythical Demon Mother.