I don't know ... I remember using a paint program where something like a flood fill, actually ran before your very eyes... at something like 4-5MHz there isn't a lot of CPU to do your bidding so game logic, music, graphical rendering all takes a slice and you don't even have any kind of preemptive scheduler to make sure everyone stays in time. I'd say with this kind of game the developers were more focused on the game mechanics. The graphics were just "good enough" for what they were trying to do.
The C64 ran at 1Mhz. Other contemporary CPUs that were clocked faster tended to take multiple clock cycles per instruction so it came down to the same.
