The most relevant thing to tell you is that this movie is a boat-load of fun. Fantastic action, an unreal setting with incredible depth, a tight pace, and a complete feast for the eyes
The characters are likeable, and the love story is not belabored.
The forest is rich and exotic. One of my doubts since they started releasing stills was that planet Pandora didn't look all that different from Earthly forests. But when you get on the ground, when you see the colors in the corners and the wonders in the sky, it's a whole different story. One of the best cinematic alien planets ever.