So, I finally got through the entire movie last night. What a freaking mess.
First off, there are like FIVE antagonists in the film:
1. The people who murdered John Carter's family
2. The Union Calvery
3. The Tharks
4. The Thern
5. The Zogdangan
It's just TOO much to follow in such a short period of time. The Thern were especially ridiculous. Immortals who help species to destroy their own worlds as sport? Matai Shang specifically states they don't actually get involved, yet in later scenes, he's extremely involved, directing and guiding Sab Than.
The film would have played much better if Carter was a Union soldier in Arizona that stumbled upon the gold mine and medallion. No unnecessary backstory about his family's murder or being a Confederate, etc. The Thern were absolutely unnecessary, as was the subplot between Tars Tarkas and Tal Hajus, where it was really unnecessary to see the latter beheaded.
Visually, the film was amazing. The Tharks looked extremely real as did the airships (loved the retro design). But the subplots only made the story more convoluted and when the final scene requires a voice-over, you know you're watching a bad movie with problems. It's really a shame because there's a good movie in there somewhere, had the right people produced and edited it.
And finally, Michael Giacchino's score completely underwhelming. So many cues sounded like LOST cues re-purposed. There was no central theme, no theme for Carter or the Tharks or the citizens of Helium (another poor choice - helium? Come on). It was just music for music's sake and didn't enhance the scenes.
I have to give this film 1.5 stars out of 5 and that's only because of Taylor Kitsch and the CGI team.