I've had a report that both your game and mine (Galaga) run at crazy speeds on the Retroarch port of VICE. Have you seen anything like that? Maybe warp mode is not deactivating after the .prg has finished loading from d64?
Yes, someone reported the same thing to me. And I think it's a warp mode problem too that stays active for some reason. On VICE for PC it works flawlessly. I don't think we can do anything about it. It's a RetroArch problem.