The phrase "mutated monsters" refers to creatures that have undergone genetic mutations or changes, causing them to become abnormal, dangerous, or monstrous in appearance or behavior. Full definition
In Rogue Stormers, players take control of rebel knights called Dieselstörmers, and fight alone, or with up to 3 friends, against mutated monsters who have overrun the oil rig city of Ravensdale. (black-forest-games.com)
However, original plans for the game had it set on a space station infested with mutated monsters, with players sent to rescue someone from a cult. (gamerant.com)
There's a version of Annihilation that's all killer, no filler — just hardcore women fighting mutated monsters — but that would make for a more fleeting and less essential science fiction. (relevantmagazine.com)