Re: What we need
I should also add that- although I'm far less familiar with the C64 than the Atari 800- as far as I'm aware, the former also benefits from custom hardware scrolling, hardware sprites and character-based graphics that allow it to outperform (e.g.) the Spectrum on most games despite its slower CPU.
Unless it's a CPU intensive game that doesn't benefit from such features (e.g. 3D games) in which case it'll suffer.