There are several things that have to be done for this:

• Decide for a stable working Linux distribution that provides access to the video and sound hardware.
• Make the emulator(s) work.
• Build a launch menu that allows for selecting the console and or the video game.
• Build a hardware controller interface that allows you to connect real video game controllers.
• Build a case that contains the Raspberry and the connector(s) for the controller(s).

via SNESDev-RPi: A SNES-Adapter for the Raspberry Pi | petRockBlog.

This leads us to the end of this post. So far, I did not speak about a case yet. Having some experience with other laser-cut cases I already started to design a case for the Raspberry that also contains ports for two SNES connectors. When this is finished I will write about it in another post.