A cut short found on one of the animators' deviantART accounts has a similar idea with Robotnik singing "It Still Ain't Easy," also by Baldry.
Hey, It's That Voice!: Voice actor GameBuddy has appeared in every volume. A few of his credits include Sonic, Shadow, Knuckles, Tails, Eggman, Mighty, Bean, Big, Tails Doll, The Penguinator, Heavy, and Doctor Mario. Needless to say, this often leads to Talking to Himself.
Along with Game Buddy is Faulerro, AKA The Chio, also appearing in every episode, providing the voice of Knuckles and Dr. Eggman.
Also appearing is Kira Buckland (Rina-chan), who makes a few appearances following Volume 3, usually as Elise, Amy, Rouge, Bunnie, or Sally. Oddly enough, these are usually in Flash Twister's shorts.