"The Game Genie does not work with Super Nintendo games that contain a performance enhancing chip (e.g. Super FX, SA-1, and S-DD1 chip) such as Star Fox, Super Mario World 2: Yoshi's Island, and Street Fighter Alpha 2. However, it is possible to modify the Super NES Game Genie using wiring and modified pieces of a PC Connector Board." -wikipedia

i believe that is true although. Star Fox uses the Super FX chip which caused alot of issues with several other addons. most accesories are designed to take use of the standard SNES hardware because there werent that many Super FX chips which made it unpractical for other addons to take advantage of the hardware.

painguy1