I liked the environmental theme, but Tampa is a military city with MacDill Air Force base & U.S. Readiness Command headquarters so when the audience was watching "Marines" getting killed for following orders, it was much quieter than perhaps in some other cities. I wish Cameron had explained more background of Earth-what the "good stuff" they needed was used for or how the commercial enterprises were allowed to use Marines or else if they had just been mercenaries out for money. The effects were wonderful - loved the science end of human brains melded with cloned alien/human bodies. The ecology message depicted in fantastical plants and animals was exciting. Thanks for a great movie.