Survival games are already a thing, though.

So? SurvivAL is not the same as survivOR.

Seems like an insufficient difference for two genres that are so distinct. Plenty of opportunities for confusion.

Action, Adventure, and Action-Adventure are all different genres. I think people will figure it out.

Those aren't words that can easily be confused for each other due to accents or minor variance in pronunciation. And besides, we already have a genre name for Vampire Survivor-alikes. They're bullet heavens.