I'm quite a derp when it comes to the actual modding, but Starfox 2 used the SuperFX 2 chip, as opposed to the original SuperFX chip used in the original Starfox. Does the cartridge sacrificed for usage in this project contain the correct SuperFX chip?
Starfox 2 will run on a SuperFX chip, although I believe it won't be quite full frame-rate. I believe the SuperFX can also be overclocked to improve performance a bit, if I recall correctly. Doug would have a lot more knowledge on anything related to Starfox 2 reproductions.