Technically, it's quite an achievement. For this alone, it should be seen.
However, it's basically "Dances With Wolves" in space. White men are the bad guys and blue people are the poor oppressed natives who fight off the technically superior white men with their sticks, rocks and arrows (along with some "divine intervention").
The characters are not much better. They are very two dimensional (a more positive review would call them archetypal).
The script is passable and the special effects are spectacular. If the plot and characters had been there too then this would have been the clear winner for Best Picture.