Nintendo Switch Online hasn’t even been out for a day and hackers have already found a way to upload new NES games to its existing library.

The creator of the project, [PortalRunner], instead turned to Squirrel, the Portal 2 scripting language, and set about porting an existing NES emulator called smolnes to this scripting language.

Nintendo hid a load-your-own NES emulator inside a GameCube classic Unused feature has been hidden in Animal Crossing for nearly two decades.