One of the… I'm going to say "dependencies for enjoyment" in many – I might even say "most" RPGs I've run (or run into) in the last few years is a deep knowledge of the genre — not just the genre for the setting, but the RPG genre of the game in question.
So… like this: once upon a time, all you really needed to know when starting to play D&D was "there's magic, no guns, and weird monsters." Same was true, basically, for Traveller or whatever.
Maybe that's still true for 5e versions of those games. Probably is. Anyway.
But there are a WHOLE BUNCH of games/settings out there now that drop a tremendous amount of signal when trying to reach a new gamer, because that new gamer doesn't have the decades of previous gaming exposure that informs the game designer's decisions for a game.
Dungeon World, for example, is fun, and it works with new players, but it doesn't work as well – there just isn't as much there – for the gamer who never played the old versions of D&D DW is reflecting. Ditto Black Hack or whatever.
Same thing is true for genre mashups: Steampunk Planetary Romance isn't inherently cool or interesting as a concept if the person you're sharing it with isn't familiar with the "pure" components of that salad, you know? It's just weird sci-fi with wood ships and a lot of brass and goggles. It might work for the player, but it won't work for the intended/expected reasons.
Masters of Umdaar is
phenomenally boring not especially compelling if you didn't grow up on the right cartoons, you know?
I run into this constantly when playing with my kids – lots of stuff I find interesting/entertaining… until I realize that for all intents and purposes, my kids just don't Get the Joke.
First, I need to run the original games everyone's ironically riffing off of, before we can get to the new stuff, or it's not a nuanced re-envisioning for them. It's just… weird and kind of confusing.
When I run a game that doesn't have that problem, it's almost always something only trying to be itself.