The main hero of Returnal has a very short, formal looking hairstyle and she appears to be in her mid 40s, which is interesting that they're going against most expectations in that sense. Normally most video games try to make a female lead younger and generally more attractive like Lara Croft in Tomb Raider or Tifa from Final Fantasy, as it's less common for an older woman to be the hero. Just an observation that makes this game unique.
As far as the enemies, Final Fantasy Spirits Within might be Returnal's visual inspiration?