Saw this movie yesterday during my day in Ocala. It was fun especially since I had reread the Edgar Rice Burroughs book it is based on a few months ago. That's
A Princess of Mars.
http://en.wikipedia.org/wiki/A_Princess_of_Mars
Doubt if you see it in 2D it will make much of a difference. I saw very little special effects in this movie that you would need 3D to appreciate.