Mash-ups don't get me very far these days.
See, I play with my kids a lot, and they don't know the baseline genres well enough to appreciate mash-ups of those genres.
Which is to say, they just don't get the joke, yet.
At the risk of repeating myself, I'm going to dive into this a bit more.
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 associated 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. The premise was simple and straightforward.
Still true for 5e versions of those games, probably.
But there are a WHOLE BUNCH of games/settings out there now that lose a tremendous amount of signal when trying to reach a new player, because that player doesn't have the decades of previous gaming exposure that informs the game designer's decisions for a game.
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. Now, that might still work for the player, but it won't work for the intended/expected reasons.
Masters of Umdaar is… 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 – stuff I find interesting/entertaining… until I realize that for all intents and purposes, my kids just don't get the joke.
So first, I'd need to run the original games everyone's ironically riffing off of, then we can get to the mashups. Otherwise, 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.