After six installments based in Ancient Greece, Kratos' upcoming adventure - due out on PS4 in 2018 - is themed around Norse mythology. However, the franchise could move on to the Egyptian and Mayan eras in the future, director Cory Barlog told GameInformer.
"The Greek games were the Greek era of God of War," Barlog said. "Moving on, the next mythological belief system he interacts with became the Norse era of God of War. But we may end up going on to the Egyptian era and the Mayan era and so on and so forth."
Given that the newest God of War still doesn't have a release date (sometime in "early" 2018), we shouldn't expect any hard details on future games for quite some time. But it's always fun to look ahead and think of what's to come with the popular PlayStation franchise.