Basically, an AI that can create, rig, and texture 3d models and game environments (by extrapolating from collections of reference models, according to user input), and that can set up physics and mechanics (assuming that the AI has access to a 3d modeling studio and a game engine, both designed for compatibility with the AI, or as a component of the AI), all according to user commands (and allowing for tweaking and optimizations of models, rigging, mechanics, etc, by the user).
An example of user commands would be something like: "Gaming AI, create a casual style* male model, European build, 6'5", fit and slightly skinny, with red scaly skin, green eyes, a reptilian tail, demonic wings, claws, sharp teeth", etc. The user probably wouldn't add all of these characteristics at once, but rather one at a time, tweaking each feature via AI commands or manually.
*"casual style" is a fictional "style class". Style classes would refer to the visual style of the models. Possible example styles include "cartoon", "abstract", "gothic", "steampunk", "serious" and "realistic".
Here's another example of user commands, for a environmental model: "Gaming AI, create a serious style house, Victorian, two story, white with beige trim, with porches and shutters. Give it a creepy aesthetic." Again, models could be created and modified or have features added in a step by step process, in order to tweak and refine them.
I believe that such an AI would significantly reduce the amount of time, labor, and difficulty involved in designing games; making games cheaper and easier to produce, and making game design available to everyone. A variation of such an AI could also be used to create 2d artwork and animations.
But is such an AI even remotely possible? And would it take a supercomputer to run the thing? (I'm under the impression that such an AI would need to be capable of learning and adapting, and would require a massive and expansile "association library"*—including 2d and 3d models, and verbal and textual speech—as well as near human intelligence)
*if the term "association library" doesn't exist, or doesn't currently relate to AI, Then I just made it up. According to my made up definition, an association library is the library of programmed or learned associations that an AI uses to generate responses, and to, in this context, generate 3d models; and probably to write or select code as well, in order to set up physics and mechanics and the like.