I must admit, I'm really impressed. For a high-budget "military" shooter, that looked very oppressive and atmospheric. Love this idea about switching characters as they die, hope it stays through the entire campaign in some capacity, seems interesting, and if they use it right, it could provide an unique twist to the genre. Still, I expect they'll quickly revert to a standard character focused story, but hey, at least we're getting a great intro. Reminds me of "Saving Private Ryan", where the opening scenes are easily the best and the most powerful part of the movie, doing the best job of portraying the chaos and brutality of an open conflict.
The visuals are great as well, some of the best I've ever seen... though I'm a little bothered by that blue lens flare when looking at the sun, it just doesn't fit the aesthetic they're going for. Not a big deal, but still, worth mentioning.