You've come across one of my embarrassing secrets. I am a self-styled master! Hehehehe.
Pokemon Stadium and Pokemon Stadium 2 are fairly accessible, yes. The announcer, while repetitive, is quite accurate. If you can manage battles in RBY/GSC, you can manage battles in Stadium or Stadium 2. A few things of note, however:
1. Rental pokemon. These have levels, stats and movesets that a sighted person would have to tell you or that you would have to figure out by experimentation;
2. Held items. Much as in GSC and onward, that particular feature isn't totally blind-friendly, even if the games themselves are. You may need a little sighted help if you want to equip x pokemon wity y type of item.
3. Mini-games; I don't believe any of these are truly accessible, except MAYBE one or two.
4. The library; this involves "lectures" that scroll across your screen and then questions you have to answer, not to mention trainer fights that are a little more specific. A little sighted help is required if you don't want to tear your hair out.
5. Your room; as in the GSC games, it's useless if you can't see.
A few observations about pokemon in general, on handheld consoles for playing: it seems that they get more and more accessible as they're released. RBY, for instance, required you to know precisely where and when to use most HMs (Surf, Strength, Cut), and was rather tedious late-game...not to mention that the safari zone's a pain in the tail. GSC's only true hangup is the Ice Path, where you slide about on ice and sometimes have to push boulders around on ice, and you're not told when you're sliding. Even a simple whirring sound while sliding would probably have been close to enough. The 3rd generation on the GBA (Ruby, Sapphire, Emerald), are even better yet. There are some small issues you might need help with (such as a turnstile puzzle in the sixth gym or maybe a teleporter puzzle in the eighth, and definitely the cracks in the floor going up the Sky Pillar), but I managed to beat that one with the least help of all. Every pokemon has itss own cry, generally speaking (even if some, like Machamp and Slowbro for instance, are similar); attacks make different sounds (the better the generation, the more definition these get). The items menu is a bit of a pain (for this reason I often over-train so I don't need potions or other items in a pinch), and stats/personalities (personalities in advance generation only) are also somewhat annoying. Overall though, the console games are fairly good. The Stadium games involve virtually no explanation and as I said: if you can play the consoles, you can play the Stadium games with little difficulty. I've beaten the second one, am still working on the first one. Which reminds me...that Juggler has to die! Stupid Horn Drill!
Now, as for Pokemon Colosseum on the Gamecube? I'm not 100 percent sure but I don't believe it's accessible, because you don't make a sound when you bump into walls and battles, though not real-time, are slightly more involved. Besides, there are puzzles and such. I'm not totally sure on that one, however.
I'm waiting to see how accessible Diamond and Pearl are. I've mainly jumped off the fan-wagon (if I was ever on it) because they just keep screwing with things (GSC was my favourite generation, and to this day I have a competitive L100 team that hasn't yet lost, and I've been in some mighty hairy fights)...but I'm curious to see what they will have done, both accessibility-wise and difficulty-wise.
I hope I was of at least some help.
Check out my Manamon text walkthrough at the following link:
https://www.dropbox.com/s/z8ls3rc3f4mkb … n.txt?dl=1