From some of the reviews I've read/watched and walkthroughs on YouTube, it seems like this game had an absolutely ridiculous amount of potential. RAD could have designed it to way more fun from the very beginning. I mean for TPS's, weaponry, gun play, enemy AI, and enemy variety is key. I think they got the weapon handling fine, but failed miserably on enemy AI and the types you encounter.
And speaking of encounters that's something that must carefully designed in these kinds of linear games. TLoU was absolutely brilliant in both pacing and encounters.
I also kept reading and hearing about how RAD didn't include enough use of the awesome weapony. That to me, it just doesn't make sense why they wouldn't focus on that more and implement that into well thought encounters.
If 65 metacritic is the average for this, then Killzone SF should probably be ~80 because seemed like more of shooter game play wise, the campaign wasn't entirely boring, and it has a good muiltiplayer.