Peter Criss was dubbed because he wouldn't show up to do looping (re-recording lines in post-production). His voice was dubbed by voiceover artist Michael Bell, who did a lot of work for Hanna-Barbera. Bell appeared in Rollercoaster (1977) which has a main filming location in common with this one: Magic Mountain.
The other members of KISS were upset by the fact that most newspaper print ads for the movie featured photos of Gene Simmons that were larger than, and seemingly overshadowed, those of them.
Almost all of Ace Frehley's fight scenes were performed by an African American stunt double, Alan Oliney, made up to look like him. In his autobiography "No Regrets", Frehley noted that he was battling alcoholism during filming, and would repeatedly leave the set due to boredom. Oliney is also mentioned in a booklet of liner notes for Kissology: The Ultimate Kiss Collection Vol. 2 1978-1991 (2007), wherein Frehley talks about convincing others that Oliney was actually him doing the fighting with a quip about "taking gymnastics in high school".
According to Paul Stanley in Kiss: Beyond the Makeup (2001), Ace Frehley often failed to show up for shooting, so Frehley's stunt double, Alan Oliney, an African American, had to act in some scenes and fill in for Frehley on some of the fight scenes. Oliney's voice was also overdubbed to sound like Frehley's (there are differing versions as to whether Frehley or a sound-alike did the overdubbing).