Proving that Prequels Predating Prequels isn't a good idea, we have the most recent God of War game, Ascension that attempts to explain how Kratos began his god-murdering journey yet crucially doesn't explain why Kratos murdered his family and thus failing as a prequel.
Although Ascension isn't that good compared to other iterations, it's still fairly decent and despite the game should've been planned and tested a hell of a lot better, I'd tentatively recommend it for those who didn't get enough of the Ghost of Sparta with all of the other games.