Insectoids

Major plot point of the game is that the seemingly barren planet that acts as the premise was inf act previously inhabited. Through an unknown act of self assured the destruction, almost all of the population was wiped out save for a small pockets that survived. Even then the pockets that survived never stayed the same, instead mutating or undergoing drastic changes as a result of the planets now decaying condition.

One such pocket of survivors ended up becoming drastically mutated beyond recognition, slowly gaining insect like properties and attributes.

I bounced between multiple different levels of "insectification" deciding how much much the denizens would have transformed, how grotesque would their new forms be. 

Much of their body is coated with an insect like carapace, rigid in some areas but mostly sleek and flowing. Their muscles are exposed and visible but protected underneath the the large plated shells adorned around their bodies. The smaller group act as drones and scavenger while larger specimens would have sometimes multiple recently grown appendages, the number of which vary upon size and the level of mutation.