Saw this one tonight: fun, but a bit unfocussed overall. There's some great stuff at the end with the Sarah Palin-esque President and the U.N., and while the ending is extremely derivative it's fun in a cynical kind of way. mediumdave is right in that the first third is the strongest, and loses steam when the main characters travel to Earth. It's a pity they didn't do more with James's Aryanification, but it's a lean movie (Running 1hr25mins) and has that feel of a film that simply ran out of money before they could shoot the connective tissue that would've rounded out the story. You get the sense they were trying to cram several years' worth of story threads into 85 minutes, and the result is a film that seems to regularly distract itself with stuff that just isn't as fun as the actual Space Nazis.
This is especially true of the villainous/stupid (Pick your favourite) fashionista/PR consultant character, who literally does not do a single thing throughout the course of the film that makes any kind of logical sense. Not a thing. She's a walking black hole of plot, and the filmmakers seem determined to only make her even more bizarre as the film goes on. The problem is, she's actually kind of irritating as a personality so any enjoyment we're meant to glean from her wackiness is lost.
However, the effects are surprisingly good, there's some excellent art direction and costume design on display (Love the steampunk-ish Moon Stormtroopers) and Laibach's score is awesome. Like MD said, keep your expectations low and your blood alcohol level high and you'll have fun. It's not quite the cult classic in the making it wants to be, but it's a fun diversion.
Edited by Workyticket - 5/1/12 at 3:34pm