 A departure from his focus on musical games, "Ninety-Nine Nights" was Mizuguchi's attempt through an action game to tell the story of a massive, international conflict as viewed through the eyes of various factions.To facilitate the completion of "Ninety-Nine Nights," he traveled regularly between Japan and South Korea to work with "Ninety-Nine Nights" external developer, Phantagram.Mizuguchi also oversaw the development of "Gunpey" (for PlayStation Portable and Nintendo DS), an update on the puzzle franchise originally created by Game Boy creator Gunpei Yokoi's development team, Koto Laboratory.