This is the biggest retro store in Ahkihabara and I think in Tokyo as well. It was two floors of nothing but old school video games, this was the floor with the more interesting stuff I felt so I asked if I could film some in the store and they did not mind, Thanks again dudes! I picked up Chrono Trigger while I was there with the original box and everything for 1300 yen. Lots of really amazing things here, if you are in Ahkihabara I would recommend going to just see this place with your eyes. Also sorry about the shaky camera I was kinda in sensory overload while I was in there I was so excited!
Here is the address that you can put in Google that is the building where Super Potato is located:
Tōkyō-to, Chiyoda-ku, Sotokanda, １丁目１１−２ 北林ビル
It is very close to the train station too!