Are you on about God of War 2005 or 2018? I'd imagine 2018, and if you've just done the main stuff, I wouldn't say you missed loads, just more lore and weapons and stuff. I wouldn't call it fluff, as at no time during my Platinum did I feel anything was a chore (IIRC), and even the boat travelling between areas is covered by excellent stories and banter with the 3 lads. Oh, and the Valkyrie fights, which are good. And probably the hidden stuff in Niflheim.
