I'd love to see a proof of concept game to showcase a new brand of AI. Make an "open world" game that is just a small city, say no more than 4000 NPCs–men, women, and children. Have the street layout be procedurally generated based on seeds that make sense (a "downtown" layout, an "expansion" layout, a "rich part of town" layout, etc). Then procedurally generate the houses, stores, and industrial places, inside and out. MAKE EVERY BUILDING ENTERABLE. It could easily be done under 10 gigs by having a set of 100 or so textures and just varying the color layer and material layer to give different carpet, wallpaper, paint, upholstery, and siding. Then you just model the furniture, utensils, books, etc. That's point one to showcase.
Point two would be far more difficult, and that's AI. Meaning AI that actually has relationships. Give them simple scripts (wake up, toiletries and breakfast, go to work, come home, play with kids, talk to neighbors, make love to wife, go to bed), and have the NPCs all interact with one another. That's the trick. The interactions and lines could even be the same every fucking day (to save on space); the point is just getting them to interact and–here's the kicker–respond APPROPRIATELY to change in their lives, no matter what that change is.
Then you drop the player into the city and tell them that they can do whatever they like. WHATEVER they like. Steal a car. Crash it. If you crash it into another car, you stop that NPC from getting home (maybe forever). An ambulance and police car come. The time this takes is based on whether there were witnesses (and how quickly they saw it happen). Kill the medics and steal the ambulance, drive to the NPC's house. Listen from outside the window. His family wonders where he is. Cop shows up later. NPC's dead, he says. Their script now changes; they're grieving. Next day, you talk to the widow. Over the course of in-game weeks, you console her. And then bed her. And then her daughter. You get caught, widow screams. Your character is now poisoned to that NPC and family forever. She calls the cops. They come to the house. SHE GIVES THEM A DESCRIPTION OF YOU. Now you have to be careful in the city. These aren't like GTA cops; they actually remember. Unless you kill them all, of course. But then the townsfolk are up in arms themselves. Volunteers with guns roam the streets instead of cops (just give them the cop beat script to follow). Eventually you just can't go anywhere.
Or maybe not. Maybe you shoot up the school first thing and are taken out in a blaze of glory.
Maybe you go to the print shop and apply for a job. You find an apartment, take it, the job, and live a normal life. Find a cute NPC girl at the grocery store; talk to her, start a relationship and a family.
Maybe you become a cat burglar. NPCs start locking their doors and buying guns.
Maybe you just cut down trees in public places. Maybe you leave a car sitting in the middle of a road. You stop traffic and keep NPCs from getting home on time. Maybe you blow up the factory. Now it has to be rebuilt; NPCs are less happy because they have no jobs.
It doesn't have to look good. It doesn't have to be fancy. It doesn't even have to be optimized. Hell, it can be no more "advanced" a proof of concept than Facade was for the concept of "full user typing input." It could even be 100 gigabytes. I JUST WANT DEPTH.