Alita is James Cameron's follow up to Avatar. A 'discarded' robot from the wonderful world floating above a dystopian, crime riddle, city is the focus of the movie. It turns out, as the title tells you, that Alita is more than discarded trash, she is an elite battle machine. It takes some time for her to figure this out, but once she does she is intent on taking out the crime boss. Alita is a CGI representation of Rosa Salazar that has crossed into the uncanny valley.
Mahershala Ali is the owner of a super-advanced and gruesome cyborg-only roller-derby league. Roller-derby is a lot of what James Cameron chose to focus the story around. Whip It was a much better roller-derby movie.
Cameron uses some future tech that would feel at home in the Terminator universe. The cyborgs can continually swap out body parts and upgrade them with more and more powerful weapons. Christoph Waltz portrays Dr. Ido, the smartest scientist on earth. He helps create some of these weapon upgrades. He also leads a double life as a bounty hunter to capture evil cyborgs.
The movie tries to set up a good versus evil battle but every character aside from Alita is on both sides. It makes it very difficult to find characters that you can root for without hesitation. Add in that minimal character development and backstory are presented before any fight or double-agent reveal, and this movie is just a mess.
I never felt myself rooting for Alita in this movie. When the biggest crime boss is just a professional sports owner I knew the stakes were set too low. As every single character turned from good to evil or evil to good I lost interest. I'm glad I skipped this movie in theaters. I have little faith that Cameron's next four projects are going to be very good; Avatar 2, Avatar 3, Avatar 4, and Avatar 5.