hmm.. somebody had problems on Mister.
Mister worked NTSC but VIC core tried act like PAL... or something like that
Viewing post in Cheese And Onion (VIC-20) comments
Thanks!
I can now confirm that the game runs fine on MiSTer too. I only had the settings for the screen center set to "both" (horizontally and vertically centered image). I never had issues with this setting before. Resetting to "none" fixed it.
Anyway, it would definitely not have been an one-life longplay on MiSTer, since of course you cannot create savestates with it ;-)