Use the clone Kratos and be sure to stun them. Don't forget your other powers like slowing down time (so to speak). Use them OFTEN, so keep track of the recharge times. I use them as soon as they are available. And remember the different blades have different powers.I find the Hades blades were most useful for the first wave since the attacks from the rage meter hits everyone in the room and it reaps life.
Medusas ... avoid them as much as you can. Get a few hits in and then dodge out. Keep dodging the beam so you wont freeze. I would not advise using magic against them since it gets harder when you have to face 2 Medusas and 2 Sirens. I'd save the magic for them.
I beat it on hard and very hard. Hopefully my advice was helpful. In all honesty I didn't find it hard at all. I thought Ghost of Sparta was harder. There is a section with a few wraiths and a cyclops or 2 after Atlantis, pretty late in the game. Now that was HARD.
