The game that later became "Pac-Man" began development in early 1979 and took a year and five months to complete, the longest ever for a video game up to that point. Iwatani enlisted the help of nine other Namco employees to assist in production, including composer Toshio Kai, programmer Shigeo Funaki, and designer Shigeichi Ishimura. Care was taken to make the game appeal to a “non-violent” audience, particularly women, with its usage of simple gameplay and cute, attractive character designs. When the game was being developed, Namco was underway with designing "Galaxian", which utilized a then-revolutionary RGB color display, allowing sprites to use several colors at once instead of utilizing colored strips of cellophane that was commonplace at the time; this technological accomplishment allowed Iwatani to greatly enhance his game with bright pastel colors, which he felt would help attract players. The idea for energizers was a concept Iwatani borrowed from Popeye the Sailor, a cartoon character that temporarily acquires superhuman strength after eating a can of spinach; it is also believed that Iwatani was also partly inspired by a Japanese children's story about a creature that protected children from monsters by devouring them. Frank Fogleman, the co-founder of Gremlin Industries, believes that the maze-chase gameplay of "Pac-Man" was inspired by Sega's "Head On" (1979), a similar arcade game that was popular in Japan.