There's really not much to the zero-g fight, and it'd pretty brief, so it's not something that would "save" the movie. But really, I'm not sure the movie needs saving; it's really not bad and almost completely inoffensive. I liked it at least as much as Minority Report, and if it didn't have to live up to the original Total Recall, it'd be as good as any other perfectly passable barely-scifi action movie.