Traverse the City
Kratos is standing atop a cliff looking out to the Temple of Helios. Perhaps there he can find some answers as to why the sun has fallen. But first he must get through the city of Marathon. Too the left is a chest containing a Phoenix Feather. Make sure to snag it before continuing down into the city of Marathon.
Move to the right and climb down the edge of the cliff. Stop at the power up chest before finishing the climb to the city of Marathon cursed by Morpheus. The city is covered in Morpheus's heavy fog and is teaming with new unworldly creatures for Kratos to decimate. Inside the boarded up building at the base of the cliffs is where Kratos encounters his first undead enemy. After using the Save Alter to the left of the structure, enter the structure ready for a fight.
After defeating the Shades, maneuver through the building, shattering any boarded exits that lie before Kratos. Passing through the second area, take the exit straight ahead to and open the power up crate and orb crate to the left. Backtrack back into the previous room and exit to the left.
In the streets of Marathon, Kratos encounters more Shades. A pack of three appears a short distance down from the exited building. Refrain from using Kratos's upgraded Blades of Chaos attack, Cyclone of Chaos, right away. Shades and Hoplites with shields use them to their full advantage after three hits of the Cyclone of Chaos. So, the best tactic is to knock them down and then unleash the full fury of the attack.
While near a target, press the 
and 
at the same time to activate a whirl wind of flaming blades. Kratos can also use this new attack in the air for a different, bloody effect. It's an incredible maneuver against non-shielded enemies--like Shade Archers.
After the first three Shades have been defeated, five more spring from the ground. The three Shade Archers in the back quickly target Kratos. Make sure to move around continuously while fighting to evade their glowing blue arrows. Once Kratos is close enough to the Archers, use the Cyclone of Chaos to rack up the combo meter!
With the area now clear, return to the health chest located near the beginning of the street. There are many chests hidden about. Open the health and magic chests that are out in the open then investigate all the buildings along the sides of the path for power up chests. Kratos finds two in the first building on the right and two more inside the second-to-last building to the right.