The SNES Classic has been out for just over a week and is difficult to find through usual retail means but that hasn’t stopped the console from being hacked. The mini console has been hacked like the NES Classic was before it, to allow additional games to be added outside of the 21 default titles.
Currently, the method of cracking open the SNES Classic to allow you to add your own games is more complicated than it will be and getting the steps wrong could brick your console.
YouTuber Skullator has put together a guide on how to open up the possibilities on your new console but explains
This is an early version of the exploit, so it’s quite a few steps and a reasonably complicated process which is likely to become a bit easier in the coming few weeks. However, if you want to get started adding your own ROMs to the SNES mini today, this is the only method I am aware of which will allow for this.
While the area of emulation and ROMs are a grey area especially in the eyes of Nintendo, the news of the SNES Classic being hacked to allow this additional functionality was just a matter of time. The NES Classic went through the same process and was opened up to adding of additional ROMs shortly after it launched.