I'd argue we're there already. chatGPT was able to create me a very basic javascript clone of Atari Breakout that worked right off the first prompt. VERY basic but it had the complete game loop, including score keeping and end game conditions, etc. I just had to copy the javascript text into an html doc and it just worked. Based on this it feels like getting to AI making more advanced games isn't that far off. (multi-modal version of chatGPT running on top of GPT-4?)