Complex sentence: The development staff was composed of Koichi Kawamoto, who was the original programmer of "WarioWare", and Shinya Takahashi, who was a longtime designer at Nintendo EAD.
Split into simpler sentences: The development staff was composed of Kouichi Kawamoto, who was the original programmer of "Wario Ware". And Shinya Takahashi, who was a longtime designer at Nintendo EAD.