Mostly instrumental music, Steroid Maximus contains elements of jazz, big band, avant-garde, soundtrack and exotica styles.
LP, Steroid Maximus' first album written by Thirlwell with guest performances by Lucy Hamilton, Hahn Rowe, Away, and Raymond Watts.
Gondwanaland also contained the "Volgarity" single and a cover of Raymond Scott's "Powerhouse"—a favorite soundtrack of many classic Looney Tunes shorts—which was originally released by Thirlwell under his Garage Monsters moniker.
He has since performed with French and Austrian versions of this ensemble, and in 2005 extended the repertoire to add a set of Foetus material for the Donaufestival.
Thirlwell has continued and expanded his Steroid Maximus stylings in his scoring work for the cartoon The Venture Bros.