I'm a little late getting my thoughts in, too. All-in-all, awesome movie, and way more fulfilling than Final Wars. There's simply a lot more heart in it, and it shows. I'll agree with Kiryugoji as far as preferences to the Next. I'll even say that I think Super 8 was a little better constructed. You could say that Ultra Galaxy is as much of a mess as Final Wars is; plot-holes abound and the non-stop action (which
is awesome), makes the movie feel, well... ADD. And Dyna's inclusion in the story, while I liked it, is pretty much random and tacked-on. His introductory scene is awesome, though ("How do you like my Ultra-fine play?"

)
Pretty much, the movie feels like someone's fan fiction put to film, but it's relentlessly entertaining. In the short runtime, I think all the major players (Man, Seven, Rei, Mebius, and Zero) get their fair share of the spotlight; it's definitely an ensemble cast.
The CG background stuff is hit-or-miss for me as well. It works best in the Land of Light, and I wouldn't change the way that the home of the Ultras was presented. It seemed unnecessary to apply the effect to
every setting, but it's the film's visual style, and you just learn to go with it (it did seem to me that the shootout with Mirai and the alien in the frozen canyons used some physical sets, but I can't be sure).