So my guidance was more of a set of hints as needed, for example "you want to boxes side by side, figure out how to do that using CSS" .. then he'd go away and talk to Gemini and ultimately Gemini would give him multiple approaches that he could try.
When it came to animation, I explained that there are many ways to animate (CSS, JS, etc) and guided him towards animated images. Basically, we "chatted" about a feature, I gave him some hints, then he went off and talked to Gemini for syntax and wrote the code. Many features he knew exactly what to do. If he wasn't sure, he'd have a discussion with me.
Basically, I was like a senior dev sounding board. He was the junior developer doing the work. Gemini was his Google/StackOverflow.
Also 32x32 limited reduces complexity a lot when trying to make a visual.
Then one day I explained how the animation worked in the Piskel app (it had layers and frames). I came back an hour later and he had that flying snake that absolutely blew me away. He originally had it at 4 frames we gave him feedback that he needs more frames to be smooth. He upped it to 8.
The graphics is where had the least guidance from parents. We were focused on the code/logic aspects.