I’ve got a few sci-fi things I’ve been tooling around with. In terms of feedback, sometimes I encounter people who miss a key part of sci-fi – it’s rarely a hard look at “What would life definitely be like with x conditions and y technology?” and more about framing things as what sort of questions and stories do you want to create.
You gotta ask the right question.
For example, if you have AI, or brain uploading, or copying people, you have a whole host of ethical questions to address as part of your setting, and probably in play.
If I want something like a adventure/shooty sci-fi like Mass Effect, where the ethical questions are more “How do I treat people in a given situation and how much violence/lawbreaking am I ok with?” that’s a different set of questions and the former ideas can quickly overwhelm them.
(To be fair, really any genre could have this kind of host of questions and focus, sci-fi just tends to bring it to the foreground quickly, and tends to be where I have to spend the most time making these curated choices.)
For this reason, I often choose to make/play sci-fi settings with a lot of things missing. No AI. Maybe very limited drones. Etc. These choices aren’t because I’m not familiar with ideas of the technology or the fact that society will be drastically different with those technologies being widespread, it’s often because that’s not the questions I want to do with this particular game/campaign.
Then the issue of onboarding.
There’s also the second issue, which is that tabletop RPGs are not a passive form of entertainment – it is critical to get people up to speed to be able to play the game. I’ve mentioned before that I’m not a fan of the 300 page setting required reading, but even short settings still require people to get on the same page for ideas.
With many sci-fi, the issue becomes a matter of which the society is so alien, and difficult, to grasp, that your group becomes lost or confused as to what’s going on. This kind of story works well in books, because you can take time to re-read sections, and think about what is happening. In a game, where everyone is collaboratively creating character dialogue, choices, and events, it can be a hurdle.
(This is also true of other genre types too, and the point after which the high concept/fictional culture is so weird to the players or has to fight it’s way through pre-conceived expectations it becomes a hurdle to play rather than a useful feature.)
The wrong answers.
There’s also the point where if you include things thoughtlessly, it naturally leads to setting up answers you probably didn’t intend. “The good guys made a slave clone army to fight and die by the millions? How are these good guys?” Oops.
One of the differences in technology vs. magic in fiction, is that technology is generally understood to be reproducible, while in some cases, magic is not quite so reliable/predictable, and this means if you do something with technology, the question comes up why you wouldn’t do it again/elsewhere? If you can cure cancer, why not cure more people? If you can bring someone back from the dead, how long until this becomes a regular use technology? And then… why AREN’T you doing this?
Obviously, there’s plenty of good stories to have around both technology that can’t feasibly be reproduced wide scale (“You can change one moment in history… but only one.”) or are being forcibly placed into artificial scarcity as a means of social control. Again though, that’s being thoughtful about where and how you place it in your setting.