Here you have a big list of Super Nintendo prototypes!
now two very rare SNES soccer games:
International Superstar Soccer SNES complete
OthersÂ Nintendo rarity:
Nintendo NES cartridge Racermate Challenge II
Sega Saturn DEVÂ unit!!!
Cool press kit:
Other demos & dev items:
TI99/4A CHISHOLM TRAIL DEMO CARTRIDGE
The seller has some of these demos, but I think that the only difference from the retail ones is the metal tip