Pratically, every Nintendo videogame have backward compatibility, GBA loads GB games, DS loads GBA games and 3DS loads DS games, but will Switch load 3DS or Wii U games? Here's a photo of the ''airport guy'', and how u can see, he's introducing an cartridge on the Switch. How we can see, this isn't an 3DS cartridge, but 3DS loads DS games, and they don't have the same shape. How we can see here, they pratically have the same shape, but the 2 cardtridges enter in the same slot. Maybe, the Switch will load the 3DS and ''Switch card'' in the same slot or in different slots, like in DS. What do u think about this?