New missed settings for me as I go through my TTRPGs which have similar themes but different genres:
Black Void: During the height of the Babylonian Empire, strange black tendrils covered Earth entirely and flung the human population throughout the cosmos. The main gameplay setting takes place on a planet (ish) called Llyhn the Eternal where humans live in ghettos at the lowest of an alien caste system which is fairly reminiscent to Bronze Age empires. Adventures and whatnot take place via exploration of the world, including within the cosmos itself, traversable by void ships – which kind of look like Spelljammer ships as they’re just sailing ships that use some kind of cosmic force to travel. A MUSH would likely be city-based play where players would be humans attempting to make things work in this very cruel, strange society.
Nibiru: Ancient Assyrians went to sleep one night and awoke in a strange environment, a space station called Nibiru orbiting the star Formalhaut. In the intervening few thousand years, citystates have emerged within the different compartments of this massive space station centered around the largest point of human activity (the city-state of Ashur). The player characters in the tabletop are Vagabonds, which are people who just kind of appeared one day akin to how humanity wound up on Nibiru, containing strange memories of other places. A MUSH would likely ignore the Vagabond piece, or expand the lost memory thing to be an accessible collective unconscious. There are no aliens or magic, but there are strange AI creatures.
Then not related to the “ancient Middle Eastern people transported to alien worlds” theme:
Working Class Space Scifi/Horror: A common touchstone for this would be Alien, where we follow the exploits of a group of space truckers faced with a horrific situation. Alternatively, a good analogous game system for this would be Mothership, which (aside from the ALIEN RPG by Modiphus which is literally Alien the RPG) is basically Alien the RPG. Working class space sci-fi is a big thing for me. Another genre that this might be referred to is casette futurism, with video games like Ostranauts being a good example of the genre.
Unknown Armies: Unknown Armies is an occult RPG. If you are aware of Unknown Armies, you probably have wanted there to be an Unknown Armies MUSH at some point. The premise of the game is that occult practitioners (the players) are attempting to understand and deal with a very strange, disjointed reality. Unknown Armies is sort of like if Mage the Ascension/Awakening remained firmly in a street level, gutter magic vibe. There are vast conspiracies of both magical practitioners and just bizarre nightmare creatures. This is a terrible description of Unknown Armies.
Bas-Lag/New Crobuzon: I mentioned this above, but it would be cool to see a MUSH set in the world of China Mieville’s Bas-Lag. This isn’t an RPG (though there was good Blades in the Dark hack for the setting), but a literary setting. I guess it would be technically considered steampunk, but it’s such a deeply fucked up setting that it’s hard to ascribe that genre to it given that it’s sort of actually like how social life was for most people in the Victorian era rather than how steampunk usually presents the world. Humans are the dominant species, with a powerful city-state called New Crobuzon, which masquerades as a parliamentary republic but is far more autocratic, maintaining its status as a superpower over the rest of the world through its exploitation of science and magic (often to the detriment of its own people).
