The idea for the dual fighter stemmed from Yokoyama wanting to create enemies with different attack styles. The tractor beam emitted by the Boss Galaga was inspired by a film in which a character's ship was captured by a circling laser. Yokoyama incorporated this idea into "Galaga", whereby an enemy could capture the player's ship with a beam and the ship would need to be rescued. Originally, rescuing a captured ship would award the player an extra life, but this was soon changed to having it fight alongside the player. This idea proved to be a problem at first; due to hardware limitations, the game could only display a limited number of sprites, resulting in the dual-fighter being unable to shoot any more missiles. As a workaround, Yokoyama made a 16x16 sprite for the ship and a 16x16 sprite for the bullets, reducing the total sprite count by two.