"The very basic fact is you could not do this engine completely as you see it there on any other system but the PS3.
We got so much physics running, so much animation running, we got the levels with 25,000 soldiers where we have to simulate the army combat which is going on on the ground we got all these dragons being animated of course. To pull of this world scale.
I think it would have been absolutely impossible on any other platform let alone a previous generation."
Listen here: http://media.games.ign.com/articles/693/693580/vids_1.html