There have been some further developments on the task of getting Krystal playable in Star Fox Adventures and other research into the game since the last post about the progress.
First and foremost, two new researchers have appeared and are working on the same problem along with Nightcast. They're sharing information and code as they work out how things work. Those two people are RenaKunisaki and Strychnine. RenaKunisaki is working pretty closely with Nightcast in the Krystal Archive Discord, while all three of them are commenting on Strychnine's research thread over at RustedLogic.
My understanding of the progress is limited, but here's what I can determine. They have successfully figured out how to switch Fox's model with Krystal's, even in areas where Krystal isn't part of the normal game data. This can be accomplished in a hacky way by forcing the game to load a new area with Krystal not being unloaded, but in this case, they're doing something more clever. Using Gecko codes, every time a new map's data is loaded by the game, Krystal's model is being loaded in as well at the end, so it's always available. This code is doing the same for the textures.
Without using this loader, individual models and textures can be manually loaded too. That's the approach Strychnine appears to be following currently. This appears to have the added benefit of allowing Krystal to have the Staff. Not sure if the Staff is actually usable yet.
Next up, they are starting to look at loading/modifying the animations. Generally, Krystal's model can use Fox's animation bones since they are so similar, but there may be ways of using more appropriate Krystal-specific animations and otherwise making adjustments that are needed to avoid quirky behavior. After that, they want to find ways to update the voice acting to match Krystal's voice and then on to more exotic projects. One goal is to mod the game to allow two players, with Fox and Krystal being playable at the same time.
RenaKunisaki has posted some open source tools and code related to this project. Some of it can already decompress data from the game disc. Other stuff available is a patch that helps do the Krystal model loading.
Some other fun things were tried, like replacing Tricky with the CloudRunner that Krystal rides at the start of the game. It yielded interesting results.
In related news, Nightcast yesterday figured out how to activate a separate executable on the Kiosk disc version of Star Fox Adventures. It is believed to be Dinosaur Planet N64, or what's left of it. The code actually runs briefly, but alas, it doesn't get far right now. The executable tries to load some files, some of which don't exist. How much can be gleaned from this code, and what it can do, will depend on how well (or if) replacement data can be inserted for these files. If they can figure it out though, it could be that part of the original N64 game could be playable. That's entirely speculation, however. Don't get your hopes up just yet.
We'll keep following these developments as they happen. I suspect within a few weeks, we'll have something that the average gamer (with a completely legitimate, purchased copy of the game) can use to modify their game to play as Krystal's model, at least in some areas. Can't wait to see what's next!
Apologies if any of this is inaccurate. I'm seeing all this as an outsider looking in and only a partial understanding. Feel free to make corrections in the comments.