It's already configured for you: https://www.amazon.com/Vilros-Raspberry-Arcade-Classic-Gamepads/dp/B01J4HTOS8/ref=sr_1_9?s=baby-products&ie=UTF8&qid=1539346610&sr=8-9&keywords=nes+retro+pi

And here are your roms (https://drive.google.com/drive/folders/0B1VEYI5Xz677UjM4bEtTektJRFk), just copy them to a USB, plug the USB into the pi, wait about 10-20 minutes and every game is on there (it transfers them automatically). Took me like 1 hour to do everything and would take way less if you are picking which roms to add if less than 1000 since downloading is the thing that takes the longest.

Plus this guy is talking about hacking his mini SNES...why go through that trouble when this is easier? If you just want the mini-SNES for as-is, I get that. But this seems like a workaround for less than optimal results.