Set in Persia, this can be a new take on the God of War series from the perspective of the Roman Empire. There are a couple of directions they can go with this: However, it could just be unique way to foreshadow the end of God of War 3 in the eyes of Kratos or something and we are all looking to far into it. Might be too similar in some instances, but it seems like a natural transition after much of the Greek pantheon has been destroyed. Jupiter would take the place of Zeus, etc. Roman and Greek mythology share a lot of similarities thanks to the Romans taking inspiration from Greek mythology (and God of War had some Roman aspects during the series), so it could be written into the lore of God of War. We've seen God of War interpret Greek mythology in a unique way, so it would be interesting to see Roman mythology interpreted in the way that Sony did for the mythos of the Greek. Roman pantheon would include the deities of Mars, Jupiter, Venus, Mercury, Neptune, Sol and others. The focus on Earth as a spherical object with the Sun present could hint towards something far greater in scope. Terra, the Goddess of Earth, of Roman mythology comes to mind.