Terrible sequel. I was a huge fan of the first & I expected better from Cameron.
The same exact villain is back, with the same goal of stopping Jake Sully. Jake flees from the war in an attempt to stop the fighting and save his family but Unobtainium still remains in the forest so the question arises as to why he would believe that him fleeing would stop the fighting? And if the humans are going to continue attacking regardless of if he is involved, why would him not participating in the war protect his family when he is the Taruk Macto and more likely to aid in stopping the humans by fighting as the war will eventually always reach his front door regardless of where he flees?
After so many years, why have the Humans not created weapons which are better equipped to stop these aliens? They show humans to have produced equipment to build more efficiently yet they have the same weapons used in the previous film. I mean even having more nets to capture flyers would've been enough to secure the win.
Humans introduce a way of transferring their memories to avatars, which is a huge knock off of Altered Carbon, which is introduced so lightly when it could have been the main plot of this film.
The CGI was good (3d recommended) but this isn't enough to distract you from the awful story (taking into account the money and 10 years taken in making this).
Don't believe the critics.