@Mr Allen J I have a few Sci-Fi roleplay ideas:
Maybe playing as some Resistance characters from Half-Life 2? If not, maybe a post-apocalyptic theme that is sort of similar to HL2.
If not, possibly The Maze Runner. (The books are great, almost done with the first book.)
If not then, possibly an Overwatch inspired RP, a Baybridge universe RP, or maybe some sort of sci-fi war themed.