Billy West declined to reprise his role as Stimpy or provide any voice work for this series. West alleged that the portrayal of Ren and Stimpy as homosexuals in "Onward and Upward" served as, in West's phrasing, 'an advertisement for NAMBLA.'
Spike TV (now Paramount Network) planned a second season in August 2004, but production stopped due to Krucfalusi's continued inability to meet his deadlines.