GB Kiss Link
Heute in der Kategorie “Obskure GameBoy-Hardware, von der noch nie jemand gehört hat”: Der GB Kiss Link
Basically, this is supposedly a "modem" (or that was how it was marketed anyway) that connects to a PC via parallel port. There you’d have some software running to either acquire games from a Hudson website or use a the games that were packaged with the modem. The modem itself would send data to the actual game inside the Gameboy via the GB Kiss feature implemented in choice Hudson games.