This post should take about two minutes for most screenreaders to get through. If you feel like that's too long, you can just skip the post's body and only answer the question in the title. I'm not your mom.
Introductory section
I was recently daydreaming some more about an idea for a single-player first-person shooter game that's been bouncing around in my head for the past three years, and I was struck with the thought that blind and visually impaired folks don't have many accessible games. So I wrote down a few ideas for how this daydream game could be accessible, and then I shared these thoughts on social media... And then somebody replied that "my heart was in a good place" but that it was "impossible" to make blind-accessible first-person shooters in any way that would be "fun" and allow people to "play well".
And it's like... I had tried to do my research on how blind and visually impaired folks already play video games today, what the community wants, and what accessibility features are already possible. The gold standard of gaming accessibility seems to be The Last of Us Part II, which you can play start-to-finish without any sort of sighted assistance — so if a third-person shooter can do it, then why can't a first-person one? Blind and visually impaired people already do play first-person shooters sometimes; any accessibility will be useful to somebody; and if people dismiss the idea of blind gaming as "impossible" out-of-hand, then very few people will even attempt to develop the technologies to prove the contrary, right?
So that comment I got seemed honestly pretty ignorant, like the type of thing where some sighted person maybe wears a blindfold for half an hour, and then assumes that actual blind people are exactly as helpless and clumsy as that.
In any case, the particular things I'd written down as accessibility features for specifically a first-person shooter were as follows:
Controller vibrations as a "virtual white cane".
This is to say vibrations of increasing intensity when approaching obstacles. As controllers have two independent motors for vibration, it should be possible to create some impression of the direction of the obstacle as well. Other forms of "haptic feedback", as it's apparently known, have been used in accessible gaming before — I'm assuming in order to distribute information among the available senses or to create redundancies. Nice idea!
Audio descriptions provided in-game.
This would be done by a figure similar to Cortana from Halo or the Hazardous Environments suit from Half-Life, and there would be some button combination for "read heads-up display". AudioQuake seems to be an early example of a first-person shooter game with audio descriptions. That game also seems to restrict the direction a player can look to just the sixteen points on a compass, which might be useful if mouse or joystick movement results in the player turning more or less quickly than thon expected.
Focusing on naturalistic binaural auditory cues.
This would include a glossary of the important cues. For the most part, though, if a game has good sound design, then the ambience and the volume and location of sound effects should be enough for one's orientation in the map and figuring out where the baddies are. The game Lost in Hound allows the player to pick up small objects, which make a ticking sound, and place them around anywhere on the map, as a custom sort of "beacon" for orientation. I think that's pretty neat.
Color contrast, simple textures, enlarged text with simple fonts
These are all such simple things to implement that it's just kinda gross that more games don't have them. I had also written down with a question mark, "Heads-up display connects to a Braille display?", since I'm not sure about that one. It would probably be mildly convenient compared to the screenreader, and there's nothing wrong with having options, right?
Sixteen clicks
This was an idea that didn't seem to have any basis in what I found when reading web articles or watching YouTube videos by blind gamers, so this is probably a nonsensical bad idea. I had just imagined that there would be some button combination which creates a series of sixteen clicks, starting north and going clockwise, with their volume indicating the distance to the nearest obstacle in that direction. Sort of like echolocation with a built-in compass, for use when the more naturalistic auditory cues have failed. It could also be that the click nearest to the intended direction would be of a lower pitch, though that might make things too easy for a lot of players.
Edit: I'm now imagining a game where the player character has a hat with a "panoramic paintball gun" on it, so instead of nondescript clicks, you get spatial information from the distinctive sound of a paintball spattering against grass, glass, concrete, wood, cloth, et cetera. That sounds kind of fun!
Aim assist and other difficulty-reducing features
The benefits of aim assist, already used by a good number of visually impaired gamers, should be readily apparent. The other difficulty-reducing features I had written down were "invisible walls mode", which prevents the player from accidentally walking off cliffs; and "superhot mode", where, much like in the popular game SUPERHOT, time only moves when the player moves, allowing the player more time to orient thonself. For a lot of players these things would probably make the game too easy, but obviously like many accessibility features, the point is that you can turn it on only if you want or need it, rather than just having some one-size-fits-all solution for the whole spectrum of disability.
Conclusion
So those were all the things that I managed to think of. Are there any ideas here that you think don't work or should be different? Are there any ideas that I missed? What have your experiences been with gaming as a blind or visually impaired person, and what would you like to see from games in the future?