You're not gonna one-shot a full, actual product.
You still have to design the individual elements individually.
Like when trying different models and prompts to generate posters for a hypothetical game, I had to generate a standalone logo first, meticulously and carefully.
You can't just throw them a prompt saying “Make a poster with this and that for a game called MYGAMENAME.”
Even if you have a genie AI you need the darn logo on its own to be able to reuse it elsewhere.
Similarly you can't just say "Make a fighting game with 900 characters”; you're gonna have to design each individual character on its own.