I liked the game, but I expected it to be better. At times I felt like the game didn't know what it wanted to be. Also the writing felt very cheap (except for the jokes) and Sam just didn't do it for me, I never really cared for him.
But I guess that are the issues that come when you do a 180 in develpment when it's already too late. You get a story that feels off and characters that are not convincing. To me, and I want to stress that this is my personal opinion, it feels like they had pretty much all the levels ready (along with the story and all that), then Amy "decided to leave the project" and Neil and Josh wrote a new story to kind of fit the levels while Bruce tried to make it more TLoU-esque in terms of gameplay which resulted in things like the poor stealth. It never really fit, but it was good and fun enough to be released. Again, my opinion, I'm not saying this is what happened. But it'd explain a lot.
Overall I still thought it was a fun game. I liked the locations, the vehicles, Nate, Sully, Nadine, the sections with young Drake (although they felt too slow or short depending on how much you interacted), the focus on exploring and climbing (!!!!) and the rope (even though it created many issues in the plot, even for an unrealistic over the top game like this the rope just messed up to many things).
Also I'd like to take the time to mention one issue that bothered the hell out of me and I never really saw anyone mention it. The way some levels are layed out/connected makes no sense AT ALL. New Devon switches the direction it faces (when in Libertalia and then later when you get there), Libertalia isn't visible when it should be (elevator and pre-New Devon level), the New Devon bridge collapse and the dramatic "reveal" of the cages that makes no sense because you would have seen them before, the harbor town and ship graveyard aren't visible, the tunnel to get there isn't long enough, the big mountain switches spots slightly, urgh. That whole island section was pieced together soooo poorly and I don't get how nobody at ND even noticed or cared enough. It's like four different teams in the studio did some levels with the main focus of making them look cool and then tossed them together. As long as it's close enough it's ok I guess. I'd have never expected ND to be so careless.
So overall, depending on what you look at U4 is by far their best or the worst game in recent years. Still good, but it doesn't match their own standards.
I am confident that they will get back on track with TLoU 2 because it doesn't look like it'll run into the huge changes U4 ran into. I have high hopes for that, even if Bruce doesn't work on it. I doubt that it was a lot of fun piecing together U4 and I'm not sure if I should be upset or happy that they managed to release the game as is.