Pretty much every news outlet has reported that, somehow, Super Smash Bros Ultimate leaked a week ago. No-one is sure where the leak came from. Regardless, details about the game have been coming out very quickly. Some are even able to play the game. However, most of the leak info comes in the form of information and audio at this point. The Krystal Archive doesn't support this behavior, and Nintendo doesn't either, suspending people's YouTube accounts over it.
With the game only 3 days away, I hope you all can wait. I will be getting my copy at midnight on Friday if possible. However, there's a couple of Krystal and Star Fox related details that are known now. If you want to avoid spoilers, read no further. If you want to see, hover or select the text below.
There are 30 slots available for additional clone/echo characters. People have mild hope that there will be up to 30 new Echo characters, opening the door for a lot of new characters based on existing movesets. Perhaps most of the character-sized Assist Trophies could be turned into Echo Fighters.
In addition to being an Assist Trophy, Krystal is also a Spirit, as is Prince Tricky. Oddly, Katt Monroe is not a Spirit.
The single-player World of Light mode features 7 or 8 cutscenes and all the bosses are now known.
Krystal can be used as an online avatar icon.
All the music was leaked. There are 17 Star Fox tracks (not counting any medleys), with three new songs coming from the Star Fox Zero soundtrack. It doesn't look like there are any brand new remixes, though. Mostly songs from previous Star Fox and Smash games.
Smash Modders have already determined how to modify textures on the models.
Smash Modders are hard at work trying to rip model assets from the game, but so far have not been able to do so.
One particular modder is looking into modding the Krystal Assist Trophy to be playable over some other character's animations.
Thanks to ShadowSnake for insight into the leak.