If you've been following the comments on the Krystal Archive, you might have seen this project by NJFox. He's attempting to make his own Star Fox Adventure game, a sequel, this time featuring Krystal as the main character. It's a bit rough around the edges, but NJFox keeps developing it consistently. I hope to see a lot of progress on this fangame in the future!
According to NJFox, the goal of the game is to fix your crashed Arwing by locating six parts scattered all over Cape Claw. Some are unreachable until you obtain certain Staff upgrades (some obtained from bosses). Eventually, he wants to add side quests and additional story. NJFox is new to game development, and is learning the programming as he goes. He's primarily a 3D artist.
NJFox just uploaded the second demo version of the game for you all to try. You can view more screenshots and download the demo versions here. If you want to try the demo, you must download both the executable file (.exe) and the Data folder that goes with it. The easiest way to get these is to select the top-level demo folder and then choose Download from the options, which will compress it into a zip folder (about 100 MB). For now, the demo is Windows only.