IGN has the rest of the boss fight :
http://ps3.ign.com/dor/objects/965454/naruto-ultimate-ninja-storm/videos/naruto_082808_cutscene.html
http://ps3.ign.com/dor/objects/965454/naruto-ps3-project/videos/naruto_082808_mandaontopfight.html
and some more videos :
http://ps3.ign.com/dor/objects/965454/naruto-ultimate-ninja-storm/videos/naruto_082808_battle_in_the_forest.html