I watched shoot 'em up as a research project on a particular villain. (Another recommendation from Aaron Stack.) The movie was okay but not entirely to my taste. It was a little raw and the liberal politics seemed a bit out of place at the end. However, the shootouts (which is why you watch this kind of film) were absolutely top notch. My one gripe with those, which are ludicrously over-the-top by design and don't aspire or pretend to be anything different, is that they suffer from "handguns are better" syndrome. Mr. Smith routinely walks over dead enemies with loaded SMGs to pick up a pistol. Really? The plot basically exists to string shootouts together, and the only real stand-out characters are the ones you'd expect - the central ones. Nobody really comes out of nowhere and steals the show, and that's fine. Paul Giamatti plays an interesting villain - cocky and sneering, but chubby and not very formidable-looking, he is nonetheless smart, ruthless, and lucky to survive a huge number of gunfights that kill everybody around him. I'm not sure I'd recommend this movie, but if you want to see it, I wouldn't tell you not to, either.
RPG notes: If you're looking to create a game with cinematic, over-the-top gunplay all over the place, put this in your to-watch list along with everything John Woo has ever done and Equilibrium. Basing a villain off the Paul Giamatti character would make for an interesting change of pace from the usual "Dark Lord" type villains that show up in a lot of games. Other than that, though, there's not much to pull into gaming here. But really, those two elements are enough from a film like this.