Excellent immersive story & non-stop action.
At first, I thought it would be hard to beat Uncharted 2 with the excellent story line and immersive gameplay. So far, this game has only exceeded my expectations. Everything is improved over the previous games from the action/fighting sequences to cinematics/graphics. The enemy AI can be a little better, but maybe I should've picked a higher difficulty than normal.
STORYLINE: As someone mentioned before, the story focuses more on Nathan Drake's relationship with Sully (at least the first 7 chapters which is what I played so far). While some of the story builds on the previous game, you can still play it and derive what happened if you haven't played the last few games. The tie-in to real historic characters and events make this game more believable and immersive.
GRAPHICS & 3D: This game looks stunning in 3D!! However, I mostly just play it in 2D and it still looks excellent. I watched a few of the cinematics in 3D just to make use of my new Sony 55HX820 :)
GAMEPLAY: Nonstop action in every level. From fighting waves of enemies to having to run from crumbling buildings and spiders, there is something exciting around every corner. There's also a ton of mazes and puzzles to keep you entertained.
My only complaint about this game (might actually be related to PS3 hardware) is that sometimes the polygon rendering starts to have glitches. This happened on a few games before when I left the PS3 on for too long.
I actually gave it a 9.5/10 because of great execution on all the areas above. The only reason it's not a 10/10 is because there is nothing groundbreaking or different. It's your typical 3D platformer, but it's just done really well and pushes the PS3 to its limits when it comes to graphics.