>Left 4 Dead (Video Games) (1)
Was used as a secondary tag with Original Work (about COVID-19).
>Helltaker (Video Game) (1)
Some dude who may or may not be magic goes to Hell to flirt with demon girls and take them back to his place. Blatant set up for harem fanfics.
I thought this game was just simple without being ambitious. But I was able to come up with a plot past the ending.
>Warframe (1)
Don't actually like this game much.
The player is a space ninja that awakens from cryostasis after the most influential multi-planetary empire in the Solar System (The Orokin Empire) collapses. The four factions that fill the power vaccuum are the Tenno (players), the Corpus (a giant corporation), the Grineer (former clone slaves), and the Infested (mutagenic disease with a hivemind).
Was used for the Richard Stallman fic to parody the F2P game mechanics.
>Guilty Gear (1)
Not a series I experienced the whole story to. From what I can tell, science invented magic, so most scientists or people with a STEM background (Dr Faust) are also magic. The US blew up Japan again but with something bigger than a nuke. There are creatures that could be anything from a mythical beast to a humanoid called the Gears that are also magic and have superhuman regeneration.
The one fic I wrote was a what-if scenario branched off one of the character campaigns in Accent Core plus R.
If I had a writing hobby sooner, the list of games I'd have written fanfiction for would've been completely different like Dragon's Dogma, Divinity, or other RPGs.