I think you underestimate how different the original game and port targets were, and overestimate how capable the machines the porters had access to as workstat

I think you underestimate how different the original game and port targets were, and overestimate how capable the machines the porters had access to as workstations were. To take a famous extreme example: https://en.wikipedia.org/wiki/Chase_H.Q https://en.wikipedia.org/wiki/Chase_H.Q. Arcade video: https://www.youtube.com/watch?v=Dfz2qofmZx0 https://www.youtube.com/watch?v=Dfz2qofmZx0 ZX Spectrum video: https://www.youtube.com/watch?v=s2aYrkofKHM https://www.youtube.com/watch?v=s2aYrkofKHM And that ZX Spectrum port is brought up all the time when people talk about great Spectrum games, while it is, at best, kind of themed the same way as the arcade original. In the case of Bubble Bobble the hardware was: https://system16.com/hardware.php?id=646 https://system16.com/hardware.php?id=646 That's 3 Z80s, not counting the sprite hardware. The result was in practice a lot of this would be done by playing the arcade machines and then attempting to replicate the feel on the target (which is why so many ports miss easter eggs), and at that the C64 did remarkably well here. The Atari 2600 Pacman is the canonical example of this going wrong.