He has appeared in and provided voices in films, television shows and video games.
[1] Outside of acting in theatre, he also works extensively as a voice actor in various anime and animated television shows and films, such as Odin: Photon Sailer Starlight, Dangaioh, Hyper Combat Unit Dangaioh, Gunnm, Patlabor: The Movie and its sequel, Blazing Dragons, Flying Rhino Junior High, Undergrads, Angela Anaconda, Rescue Heroes, Rescue Heroes: The Movie and RoboRoach.
[2][3] In 2000, Glen became the voice of Thomas the Tank Engine in Britt Allcroft's fantasy film Thomas and the Magic Railroad, replacing John Bellis in the final cut of the film.
[4] The film received mostly negative reviews from critics and was a box office failure.
Glen has also made live action appearances in several television shows and television films, such as Twice in a Lifetime, Daydream Believers: The Monkees' Story, Earth: Final Conflict, Street Time, Skatoony, and The Frim.