I posted a topic about this on Reddit a while back, but I figured I might as well post it here as well with the hopes that someone might jump on my idea.
I don't know how much of this is possi9ble, and it will require a lot of time and effort, in addition, it can only6 be done by someone with some vision.
I fooled around with fan made pokemon games a while back and realized that if you have access to the rpg maker project file you can modify and change a lot of aspects of the game. I think it might be possible to make these games accessible, if not fully, to a large extent.
A lot of these games are already complete and contain up to generation 6 and sometimes 7 of pokemon. They have an identical layout to that of the GBA/NDS versions of the game. They are mapped with tiles. That means that if you have access to the games files you can add triggers to the tiles which would make it possible to add sound triggers/loops to individual tiles. By using sound you can implement a system similar to that of Manamon where a sound would get louder if you approach a person, wall, chest etc.
Once could also add sound triggers to conversations. So if you pre-record dialogue with TTS you can simply trigger it when having a conversation. The same thing can be done with menus, pokemon and moves.
The only thing I have not figured out yet is the numbers. Things like HP and stats will be hard to figure out.
I have only modded visuals myself, but I am sure someone with a bit of development background can figure this out. These games are very high quality, some of them, arguably, surpass the originals. They allow for online play and trading in he majority of the cases.
If anyone reading this wants an example they should google the pokecommunity custom games forum. If you want specific games to look at I suggest looking at Pokemon Insurgence to see how good a game can become, and Pokemon Metal for a game that has all its resources made available including all the in-game text, stats, encounters etc.
It may also be worth mentioning that the creators of these games all make use of Pokemon Essentials, which is a asset and resource package for RPG maker. They include all the pokemon's stats, moves, menus, sounds etc. so a lot of effort is saved on adding raw data if someone wants to start a project from scratch.
Also, if anyone reading this is interested in a guide on how to make a high contrast version of these games, if you have low vision, I can do that for you. I coloured all the grass black except tall grass, I changed all the text boxes and menus to show white text on black backgrounds, I changed the HP bars to make it easier to see your current HP as well as the Pokemon's name by adding darker backgrounds and I added black backgrounds to the summary screen to make it easier to see stats and even the pokemon sprites.