Very interesting video! How does the GameGAN image discriminator work? I don't know so much about GANs but it seem to me that classifying PacMan images as real or fake would be a very hard problem because of the low resolution.

Suppose PacMan is in a corridor and there is a dot to the left of him and three to the right: ".P..." That is plausible because PacMan hasn't eaten any dots yet. But if the second dot to the right is missing: ".P._." something is wrong because the first dot to the right is still there and PacMan can't jump over dots. It must be very hard to get the discriminator to understand that the second image is fake.