After looking at Cthulhu Tech I was thinking about themes across games
So for example the Cthulhu Mythos is found in Call of Cthulhu, Acts of Evil, Cthulhu Tech, Dnd(the Far Realm), Freeport, Cthlulhu 500(card game), Arkham Horror(board game) and so forth.
Some other examples of a broad theme are Cyberpunk, Steampunk or Superhero.
What broad themes do you like to play and why?
And what kind of themes might you like to play but no RPGs exist for it. For example mysteries.