"Plants vs. Zombies" was designed by George Fan. He initially was going to make a game that would be a more defense-oriented game sequel to his fish simulator game "Insaniquarium". During development, he converted it into a tower defense game featuring plants fighting against zombies. The game takes inspiration from multiple games and movies. It took three and a half years to make "Plants vs. Zombies". Rich Werner was the main artist, Tod Semple programmed the game, and Laura Shigihara composed the game's music. In order to make the game interesting for casual and hardcore gamers, the tutorial was designed to be simple and spread throughout "Plants vs. Zombies".