I think this would have more chances of success if it focused on just one aspect of game creation, instead of trying to solve engine development, gameplay devel

I think this would have more chances of success if it focused on just one aspect of game creation, instead of trying to solve engine development, gameplay development and content development all at once. I.e. if an programmer wants to create a game, then getting the artwork in a consistent style is a big problem, and solving that alone (i.e. as a plugin for Unity or Unreal or Godot or whatever) would be both powerful and difficult. Conversely, if someone without programming skills wants to create a game, then it would be best to focus solely on the AI assistance for gameplay design with a fixed, well-known engine and an integrated well-populated market for content, and assume that they will get the content packs there, leaving that problem out of your scope but making it easy to integrate the AI-generated logic with the pre-made content packs.