This is a discussion on Game Length within the God of War: Ascension forum, part of the G; Does anyone know how many chapters there are in the single player campaign? I can't seem to find it anywhere.
Well granted I only played on normal but that hardly justifies it being only 8h when they said 14 =\ Maybe they counted the trials of Archimedes as 6h since it seems like a lot of people are having loads of trouble at that part of the game. I didn't find it very challenging though... If you've played any other GoW games you'll be fine
Actually I have put more time into the game than it shows because I have been stuck on Ch.28 for a good 2 hours and since you don't reach a checkpoint when you die/quit the time does not get saved. There is a very possible chance I have put in 14h on Hard mode while it only has recorded 10h.