Masaya Matsuura is the man behind the music and production of both Parappa The Rappa and Un-jammer Lammy. Rodney A. Greenblat did all the graphics for Parappa, a strange 2D / 3D kinda combo that must be seen to be explained. Rodney also works for Apple where he illustrated some of the company's brochures and books.
Rodney's site can be seen at http://www.whimsyload.com