Set in the realm of brutal Greek mythology, God of War III is a single-player game that allows players to take on the climatic role of the ex-Spartan warrior, Kratos, as he scales through the intimidating heights of Mt. Olympus and the dark depths of Hell to seek revenge on those who have betrayed him. Armed with double-chained blades, and an array of new weapons and magic for this iteration of the trilogy, Kratos must take on mythology's darkest creatures while solving intricate puzzles throughout his merciless quest to destroy Olympus. Utilizing a new game engine built from the ground up and state-of-the-art visual technologies, the development team behind God of War III has made standard-setting strides in giving players the realistic feel of actually being on the battlegrounds. With texture resolutions quadrupling since God of War II on PlayStation 2 computer entertainment system, God of War III, in its debut on the PS3 system, will feature fluid, life-like characters, as well as dynamic lighting effects, a robust weapon system, and world-changing scenarios that will truly bring unmistakable realism to Kratos' fateful quest. Players will have a chance to join battles on a grand scale that is four times larger than its predecessor.

Following the ending of God of War II, God of War III picks up directly after this with a stirring opening narration from Zeus discussing the actions of the rogue Kratos, who is 'commanding' a small army of Titans rescued from the Great War (using the power of the Fates). The Olympians immediately rush to battle; Helios rides on his chariot over Olympus, Hermes speeds down the very peaks of Olympus as Zeus watches on, Hercules receives the order to lead his troops down into the fray, Hades lunges off and engages several Titans in his giant form, and Poseidon (using his aquakinesis) shoots down from Olympus like a missile and performs a death blow through the chest of Epimetheus, and then manifests himself as a massive water being and spawns several water horses called Hippocampi to aid in the battle. With Poseidon as their greatest threat in the battle, having already decimated numerous Titans and soon going after Gaia herself, Kratos engages the God of the Sea and after drawing him into Gaia's grasp manages to knock a weakened Poseidon out of his godly form and onto a separate platform. The two quarrel with each other briefly before Kratos walks up and beats the Lord of the Sea savagely, finally gouging out his eyes and snapping his neck before he tosses him into the ocean. With Poseidon's death, the seas cataclysm and ocean levels rise significantly, causing a flood that appears to engulf the entire world and destroying almost all of mankind save those on top of Olympia.