This is very cool and on a lower level (more in the trenches) compared to what I did earlier in the year (i did a small writeup and built some skills [1]).
Because I am so-and-so pixel artist, the biggest unlock for me has been in rapidly iterating with graphics assets and sprites, and it's actually helped me become a better artist and animator (I built my own little tool for this [2]). The rest Codex or Claude Code seem to handle incredibly well (plus I have 30 years of programming behind me).