I was very excited for this movie as I found the first Avatar fascinating. Looking at my utter disappointment with this sequel, I wonder how much of my awe for the original was merely for graphics and being 13 years younger.
First of all, the graphics are once again wonderful. It doesn't come as "groundbreaking" as the original was, but it's still pleasing to the eye, that I would have given 3 starts for the visuals alone if the plot wasn't so dumbed down.
We follow the same protagonist and the same nemesis, with the inclusion of the protagonists children as characters of importance. Sadly, none of them are surprising or uninteresting. Sully is the classic over-protective father. The teenagers are classic teenagers, and the same nemesis is just the same guy with no interesting add-ons. Sadly, Neytiri is presented superficially as an emotional mother and not given much talk time. She was one of the most interesting characters for me in the original, so to see her drown amongst the uninteresting characters screen time was sad.
The sequel expands to include an oceanic Na'vi tribe, which have different looking bodies adapted to their environment. Sadly again, the movie doesn't do much to explore their culture and differences. Sully's family just quickly adapts to become sufficient among their new tribe.
The whole script was incredibly underwhelming, and what could have been a rich world was just like looking at a pretty person and seeing they have no unique personality to offer.