King & Balloon was the first game to be produced by Namco using a surplus of Galaxian PCB boards they manufactured. According to co-director Shigeru Yokoyama, he wanted the game to have an autofire feature with "tons of bullets" to reflect the "panicked mindset" of the player seeing the King get taken by balloons. However, the Galaxian PCB boards could not handle either of these ideas since Galaxian did not have an autofire feature to begin with, and the bullets were made faster than those in Galaxian as a compromise.