Have a look at GANTheftAuto, a fork of Nvidia's GameGAN which was trained to emulate dynamic game environments. Basically, the neural network studied the original game and then recreated the game world adding some basic movements, physics, and other elements. Previously, researchers used the model to recreate simpler games with GameGAN like Pacman but with the latest research, they decided to generate one of the most complex environments in games.
"GANTheftAuto focuses mainly on the Grand Theft Auto 5 (GTA5) game but contains other environments as well," noted the team.