We saw Avatar last week and I intended to write a review as soon as the Xmas mayhem had died down... which it hasn't quite, yet, but I have a few spare minutes tonight. Minor spoilers ahead (as if the trailer didn't already tell the entire story).
First of all, the 3D thing. For the first few minutes wearing the goggles (which happened during the 3D trailers), the effect is stunning. I haven't watched anything 3D since some Michael Jackson movie at Disneyland over 10 years ago, and it's strange the technology died a quick death - until now. Suddenly there are half a dozen big movies in theaters or about to come out. After a while, however, you forget about the 3D and Avatar doesn't make any particular effort to make you remember. Not that that's a bad thing. There are a few scenes where the effect is a nice touch, but nothing comes hurtling toward the camera at full speed. I think 3D enhanced the visual experience only on a subconscious level.
The plot is one hundred percent predictable with no twists. That was rather disappointing. I suppose other James Cameron movies have the same problem, now I think about it (Aliens, Terminator and The Abyss are three of my all-time favorite movies), but somehow it didn't bother me before. I think the difference was that those movies had suspense built into the premise, and even though most of the plot was revealed early, with the remainder of the movie simply playing out that premise in action sequences, there was still plenty of interest in how the premise would play out - largely because of various character quirks and growth arcs.
Avatar's premise is revealed in the opening scenes and after that nothing changes. No surprises. No character, other than Jake Sully, has a growth arc, and his is not clearly defined. I don't know why he continues to lead the Pandora natives, the Na'vi, toward their own destruction while simultaneously making the emotional switch to their side from the very first time he meets them. If he hadn't been told that the military would force the Na'vi from their homes if he failed to convince them to move, his behavior would have made more sense.
Grace, head of the Avatar Program, felt to me like a superfluous character when she could have been an integral part of the plot. What if her absorption by the planet had actually meant something, had perhaps provided proof that she was right about the planet's Gaia-like biology, leading to the withdrawal of the military because the people back home realized they couldn't condone destroying it? Instead, Grace vanishes and the military withdrawal at the end is completely implausible. They lose one brief battle against bows and arrows and snapping dogs, and give up forever? Not likely.
What I'm really saying is that in those other Cameron movies, which I've rewatched dozens of times, I felt invested in every single major and minor character, from the doomed roommate in Terminator to the pair of tough-as-nails smartgun operators in Aliens (also doomed). I didn't feel that for any characters in this movie. Visually, it was stunning if repetitive (there's nothing much new beyond anything shown in the trailer). The stuff-blowing-up is impressive if you like that sort of thing (it kind of bores me) and the motion-capture CGI Na'vi look pretty cool.
But while the movie is an enjoyable way to spend a few hours, I left the theater with nothing to think about, no characters to ponder, nothing to remember. Which means I'm not sure I'm motivated to ever watch it again.