Hi Rose!
I understand you don't want PR speak to be included in the introduction of the game, but you can't know what is and what is not PR speak if you don't know the game where you keep changing/removing other people's edits/additions. No, the "evolving threat" part is not PR speak for Aliens Fireteam Elite, that's literally how the game works, Xenos evolve during each match, stronger variants become more common and their number increases. You also removed the part that specifies for people that you only play as marines, no option for robots or Xenos. PCGW serves as a great, in-depth tech-focused description of games for PC gamers, so removing bits of introductions because you believe something is PR speak(or because it's not 100% tech detail) goes against this objective. My introduction was clear, short, yet very detailed about the game.
Please research more about the game or stop removing/editing other people's work on it.