Indeed. Maxwell Atoms wanted to make a sequel called the Underfist, the pilot episode was even shown as a GAoBaM Halloween Special, but since his contract ran out, instead of becoming the sequel, it just became the last episode of GAoBaM. With Mandy being president(of USA I presume) and Grim and Billy her mad scientists, while the main action goes to Jeff, Fred Fredburger, Skarr, Hoss Delgado and Irwin.