Here I am sitting with my fancy Kinesis Advantage keyboard... but hey, it turns out the person who wrote the first Kirby game didn't even have a keyboard.. they programmed the initial demo with just a trackball.

Sakurai, who was 20 at the time, says he simply thought this keyboard-free programming environment was "the way it was done," and he coded an entire functional test product using just the trackball. He even says the process led to some improvements managing the game's "data processing load," creating "a game that had a very smooth movement for a Game Boy game."