I think the requirement and the expectation do need to be managed.
"write a pac-man game for my Mac" is a little bit broad!!
The fact it is written and maybe doesn't compile first time, or the keyboard handler doesn't work or it all flickers is still incredible.
Just keep giving it feedback as detailed as possible and build on that in my experience brings fantastic results.
By default chat writes code that's easier for humans to follow ( as it told me ). I ask for optimised , efficient code - don't worry about readability .